The first step toward success with tenders is selecting the right plant for the kind of over wintering space you have.
Much of our experience with the storage of tender perennials has taken place inside our nursery’s greenhouses, but we’ve also stored them in our home — both in our living space and in the unfinished basement. We’ve also learned a tremendous amount about the storage of tender perennials from conversations with our customers, who have devised some ingenious methods for holding on to their favorite plants through the decidedly unfavorable conditions of the average New England winter.
Every gardener faces somewhat different growing and storage conditions. Your own conditions are a unique combination of light, temperature extremes, and the type of potting mix you’ve used. Because of this, it’s difficult to give general instructions that apply to everyone in every situation. We firmly believe that a gardener can learn much of what he or she needs to know about how to care for a plant simply by observation. To avoid problems, we recommend that you check on your plant frequently throughout the winter, even if it’s tucked away in the basement or an unused part of the house.
To prune or not to prune? This is a question that continues to perplex gardeners of every stripe. Throughout this section of the book, we’ve indicated when a plant can be cut back hard, either before it’s been brought indoors or during the winter. Except for a few exceptions (see here), most plants will tolerate being cut back. Plants that grow very quickly can be cut back drastically.
Watering through the winter. A plant’s water requirements are affected by its age, size, and whether or not it’s actively growing. When plants grow outside, the humidity, light, and temperature all affect how much water they use — these conditions determine how much moisture evaporates before it reaches the plant’s roots. When a plant is grown indoors, the amount of water it needs to receive is dependent on these same conditions. Whether you keep your living space very warm, heat with a woodstove (which dries out the air), or live in a house that’s built into a hillside makes a difference in your indoor ambient humidity and thus affects how often you need to water your plants while they’re sharing your home. Developing a sense of how to give plants what they need is going to keep you in much better stead than if you were following the arbitrary directions of someone who isn’t familiar with your surroundings.
Inserting your finger into the soil to test for moisture — or the lack of it — is a perfectly good way to assess whether a plant needs to be watered. You can often gauge dryness just by looking at the color of the soil at the top of the pot. If you study your plants, you’ll also observe subtle changes in leaf color when they become dry. You’ll also notice when they begin to wilt. Slight wilting is not necessarily a bad thing. It is far better for the plant than keeping the soil saturated with water — the resulting lack of air space in the soil may lead to disease.
Feed me? In general, fertilizing plants is appropriate when they are in a period of vigorous growth, and most plants that are being overwintered indoors should need little or no fertilizing through the winter. No matter what kind of fertilizer you use, when you pot up a plant, you may find it helpful to label the plant with information about when it was potted, what amendments you added, and whether you incorporated a slow-release fertilizer.
Hardy to at least 35°F (2°C)
Overwintering. Cool, sunny window. Abutilons bloom profusely in winter and should be fertilized lightly. They can get scraggly, especially in less than full-sun conditions, so don’t hesitate to prune leggy branches back hard. (See Cool & Bright.)
Propagating. Cuttings can be taken at most times of the year.
Common pest problems. Aphids are fond of abutilons. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Warm and sunny (see here). Acalyphas are slow-growing, so prune gently if you want to shape your plant.
Propagating. Cuttings should be taken during periods of active growth but before the plant blooms.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool, with bright light (see here). The cooler the conditions, the later agapanthus will bloom. When stored at 40°F (4°C), in Zone 5 it is possible to delay bloom until June or July.
Propagating. Division. This method requires considerable exertion, but is also a necessity as the plant matures. Agapanthus does have a preference for being pot-bound — tight confines encourage it to bloom. You can also grow it from seed, but this will be a much lengthier process.
Common pest problems. Scale. (See Specific Pests and Diseases.)
Hardiness varies; most are hardy to at least 25°F (–4°C)
Overwintering. Agaves are equally happy in cool or warm conditions, as long as they receive plenty of light. Some gardeners prune off the sharp tips of threatening leaves to make them more companionable housemates. (See Sunny & Warm and Cool & Bright.)
Propagating. Division of the pups that eventually surround the mother rosette. If your species agave blooms, you can also collect seed, but growing them this way is a slow process.
Common pest problems. Occasionally, scale can pose a problem indoors, especially when conditions are very warm. (See Specific Pests and Diseases.)
Most species hardy to at least 35°F (2°C)
Overwintering. Room temperature and bright light. Cool and bright conditions work well, too. (See Sunny & Warm and Cool & Bright.)
Propagating. Aloes are easy and quick to grow. Many species do not reproduce particularly quickly, however. Be patient and eventually you’ll have offsets you can divide.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). This rangey grower benefits from frequent and fairly hard pruning.
Propagating. Both cuttings and seeds. Cuttings are best taken in late winter.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright, although some gardeners have had luck storing dormant lemon verbena in a dark, cool basement. Prune back to live growth in the spring. (See Cool & Bright.)
Propagating. Cuttings.
Common pest problems. One of the best reasons to let lemon verbena go dormant in winter is to avoid insect infestations — particularly those of spider mites and whiteflies. This is a good example of how dormancy can benefit some plants. When they’re hard up, aphids can also become interested in lemon verbena. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Warm and sunny (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here).
Propagating. Will produce bulblets that are easily separated from the parent plant and potted up.
Common pest problems. None.
Corm is hardy to at least 45°F (7°C)
Overwintering. Store corms where it is dark and dry, either closeted in their pot or placed in a paper bag. Try not to eat them all — they are edible and quite tasty. (See Dark & Dry.)
Propagating. Amorphophallus corms will produce numerous offsets. It takes three to four years for offsets to reach blooming size.
Common pest problems. None.
Hardy to at least 15°F (–9°C)
Overwintering. Cool and bright (see here). This plant’s scraggly habit is much improved by occasional hard pruning.
Propagating. Roots easily from cuttings taken in late winter; also can be grown from seed.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Cut back hard at end of summer.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). It is especially important to water only sparingly in winter. In summer, when they are in active growth, they require much more water.
Propagating. We have usually grown our kangaroo paws from seed; however, it is also possible to divide plants with especially desirable characteristics.
Common pest problems. In the garden, kangaroo paws attract slugs. Slugs may be discouraged by copper barriers, but the most reliable way to eradicate them is through cultural practices that encourage air circulation and good soil drainage.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright conditions (see here) should ensure winter bloom. Shear the plant, or do more fine-tuned deadheading on a regular basis. They respond well to pruning.
Propagating. Cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Cut back in late fall to promote winter bloom.
Propagating. Cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Either warm and sunny or cool and bright (see here and here); begonias are an adaptable group of plants.
Propagating. Leaf or stem cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Either in the pot and placed in a dark place or simply inside a paper bag. (See Dark & Dry.)
Propagating. From the many cormlets the mother plant produces.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here).
Propagating. Root cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Brugmansias should be stored in their pots for the winter in cool and bright conditions. Prune to maintain a manageable plant. (See Cool & Bright.)
Propagating. Cuttings taken before flower-bud initiation.
Common pest problems. Whitefly. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Dark, cool, and moist — though make sure rhizomes stay above freezing. Dig up rhizomes before frost hits, and store in a tightly closed plastic trash bag or ice chest (see here). (See Dark & Damp.)
Propagating. It’s easy to propagate these productive plants. Simply separate the rhizomes according to size and the number of containers you want to fill. Keep in mind that even a fairly small rhizome will provide quite a show.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). You can continue harvesting peppers through the winter, too. Sometimes an older plant will benefit from hard pruning.
Propagating. From seed or cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardiness varies; most are hardy to at least 5°F (–15°C)
Overwintering. Cool and bright (see here). Do not cut back. Simply remove old foliage by pulling out individual blades.
Propagating. Division or from seed.
Common pest problems. None.
Hardy to at least 15°F (–9°C)
Overwintering. Cool and bright (see here). Given these conditions, ceratostigma will bloom happily most of the winter.
Propagating. Cuttings.
Common pest problems. Aphids sometimes like this plant. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Cestrum has a tendency to get a bit rangy — don’t hesitate to prune fairly hard to shape the plant in the fall, but avoid removing the flower buds.
Propagating. Cultivars are best propagated from cuttings, but the species may be propagated from seed.
Common pest problems. None.
Hardy to at least 20°F (–7°C)
Overwintering. Cool, bright, and dry. Do not prune — simply remove old leaves by pulling them off the plant. (See Cool & Bright.)
Propagating. Seeds or division. Because chondropetalum occurs in fire communities in its native South African habitat, germination of the seed requires exposure to smoke.
Common pest problems. None.
Hardiness varies
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. Scale. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Either warm and sunny or dormant and cool in a plastic trash bag or ice chest (see here). (See Sunny & Warm and Dark & Damp.)
Propagating. Offsets from the tubers.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Most species hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). It’s critical to keep these plants dry; let them dry out well between waterings.
Propagating. Cuttings
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here).
Propagating. Seed or cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Unearth the tubers after frost has affected the tops. Store in slightly moist peat moss, as you would dahlias. Alternatively, leave in the pot over the winter and do not water. (See Dark & Damp.)
Propagating. The tubers will produce offsets or you can take cuttings early in spring.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). Water sparingly.
Propagating. Cuttings taken from nonflowering plants.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright or at room temperature in your living space. (See Sunny & Warm and Cool & Bright.)
Propagating. Cuttings. Choose young growth and stick into a well-drained mix. Crassulas require remarkably little water, and fragments that drop into the soil beneath an established plant will often root on their own.
Common pest problems. None.
Hardy to 10°F (–12°C)
Overwintering. Dark and dry (see here).
Propagating. Propagate by planting new cormlets or from seed.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). Prune back plants by half at the end of the summer.
Propagating. Cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Dig up tubers and store in damp peat moss for the winter. Alternatively, if they were growing in a container, leave them in the pot and place in the dark. Keep the soil slightly damp. (See Dark & Damp.)
Propagating. Collection and division of tubers.
Common pest problems. None.
Hardiness varies
Overwintering. Cool and bright (see here). Daturas do tend to grow a bit rangy; feel free to prune back to a desirable shape and size.
Propagating. Seeds.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Avoid pruning just before bloom.
Propagating. Division.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). Prune hard in late summer, and repeat as necessary.
Propagating. Cuttings, although the species grows easily from seed.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here).
Propagating. Sow fresh seed in the fall. Dichondra can also be grown from cuttings, although plants will take some time to develop.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). Prune as desired to maintain a compact shape.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. In your living space, as long as there is adequate light; otherwise, cool and bright. (See Sunny & Warm and Cool & Bright.)
Propagating. Division of offsets.
Common pest problems. None.
Hardy to at least 5°F (–15°C)
Overwintering. Cool and bright (see here). Trim off spent flowers, and prune to maintain a compact shape.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 25 °F (–4°C)
Overwintering. Cool and bright (see here). Water sparingly.
Propagating. Seeds; leaf cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 5°F (–15°C)
Overwintering. Cool and bright (see here). For specific fig overwintering techniques, see here.
Propagating. Layering is the favored method, although cuttings can also be taken from mature wood. To layer, select 8- to 12-inch shoots and bury them so that only a few nodes are above the soil surface. Hardwood cuttings can also be taken after the tree has lost its leaves — preferably no later than the end of December. With either method, developing sufficient roots on fig cuttings is not a quick process — they may become established by the end of the following year.
Common pest problems. Scale. See here for suggestions on how to cope with an infestation.
Most hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). Because fuchsias need more water than do many other plants, we recommend that you store them individually. Be careful not to let them dry out completely, but don’t allow them to become waterlogged either. They may have difficulty if planted in containers that are too large. Generally speaking, pruning fuchsias is a good idea. If plants become lanky, cut them back hard. Of course, any trimming will probably result in the loss of some flower buds, but the plant will also respond with greater vigor.
Propagating. Cuttings taken in late winter or early spring.
Common pest problems. Botrytis is fond of fuchsia, and the paler-flowered forms seem to be most susceptible. In the winter months, many fuchsias are also prone to rust, which can be discouraged by the removal and disposal of infected leaves. Aphids and whiteflies can also pose a problem. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). The humidity supplied by a greenhouse or conservatory environment is best. If you lack these special conditions, mist frequently and keep the humidity as high as you can. A humidifier may help considerably. If your plant is getting rangy, prune it back hard.
Propagating. Cuttings.
Common pest problems. Red spider mites. Keeping the soil dry in winter and feeding regularly during warmer weather may help prevent infestations. (See Specific Pests and Diseases.)
Most species are hardy to at least 30°F (–1°C)
Overwintering. Wait for early frosts to kill foliage in the fall, then cut the stems a few inches above the corms. Dig them up, shake off soil, and sort by cultivar. Allow corms to cure in an airy, warm space for about three weeks. Then separate the older, spent corms that bloomed this season from the smaller new corms, discarding the old ones. Store corms in well-ventilated, dark, dry, and cool conditions. (See Dark & Dry.)
Propagating. The very smallest corms, known as “cormels,” may be saved and grown on in subsequent seasons.
Common pest problems. Glads are susceptible to a number of pest and disease problems. To minimize these, discard any mushy or unsound corms. Thrips are a major pest issue. Storage temperatures between 35 and 40°F (2–4°C) may reduce the chances of thrip damage. As an added precaution, the corms can be dipped briefly in 160°F (71°C) water, then dried thoroughly before storage. Practice crop rotation when planting them out, choosing a different location each season. If foliage appears streaked or stunted, they may be infected by a virus and should be discarded.
Hardy to at least 25°F (–4°C)
Overwintering. A controversial question. Some gardeners have successfully overwintered Gunnera manicata in the ground in Zone 5, but this requires fairly elaborate coverings, as well as electric lightbulbs and insulation to keep the plant crown warm, not to mention the cooperation of Mother Nature. For most gardeners in colder climates, growing it in a pot, which is brought inside during the winter, is probably the most reliable approach. If temperatures are sufficiently cold — around 35°F (2°C) — store gunnera in the dark. Otherwise, keep your gunnera in cool and bright conditions. (See Cool & Bright and Dark & Damp.)
Propagating. Seeds.
Common pest problems. No insect pests or diseases have dared to bother our gunneras, but persistent wind can cause damage to the leaves, especially when a plant first moves outdoors. For this reason, make sure to maintain adequate moisture for your plant, especially during such transitions, and choose a moving day that isn’t terribly windy. Alternatively, create a protective structure or shield to help your gunnera adjust to the move.
Hardy to at least 40°F (4°C)
Overwintering. Warm and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). Occasional pruning will keep this plant more compact.
Propagating. Cuttings or seeds.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). This plant likes regular watering. Frequent pruning may be necessary to keep it happy in a pot.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. In your living space, but if light conditions are not adequate, cool and bright is also fine. (See Sunny & Warm and Cool & Bright.)
Propagating. Division of offset rosettes.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here).
Propagating. The cultivars should be propagated by cuttings.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 33°F (1°C)
Overwintering. Cool and bright (see here). Heliotrope’s growth will slow considerably in cool temperatures, but it will continue to bloom. You may want to prune back straggly growth.
Propagating. Cuttings.
Common pest problems. Aphids seem to find these as sweet as humans do. (See Specific Pests and Diseases.)
Most hardy to at least 45°F (7°C)
Overwintering. Hibiscus rosa-sinensis prefers warm, sunny conditions; H. acetosella can tolerate much cooler temperatures. (See Sunny & Warm and Cool & Bright.)
Propagating. Cuttings.
Common pest problems. Aphids, whitefly. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Prune hard to soften the plant’s naturally lanky habit.
Propagating. Cuttings.
Common pest problems. None.
Hardiness varies, but few are hardy beyond 5°F (–15°C)
Overwintering. When keeping any vining or twining plant in a temporary confined space, it is desirable to limit its growth. For this reason, keep ipomoeas in as cool an environment as possible to discourage winter growth. They do best on the dry side. Alternatively, cut back the vines and store the tubers in dark, somewhat damp conditions. (See Cool & Bright and Dark & Damp.)
Propagating. Some types, such as Ipomoea indica, can be propagated only by cuttings; others start as tubers — I. batatas, for example. These are also delicious to eat, so make sure you save a few to plant in your summer containers. All of the I. tricolor cultivars are easily started from seed.
Common pest problems. The only insect to bother our ipomoeas is a distinctive one — the sweet potato leaf beetle. This beetle has a rectangular, iridescent body, and generally arrives as soon as plants are set outside in the spring. It punctures the foliage with multiple holes but doesn’t seem to hurt the plants seriously. Indoors under cool temperatures, red spider mites may also be a problem. (See Specific Pests and Diseases.)
Hardiness varies
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. Whiteflies. (See Specific Pests and Diseases.)
Hardiness varies; most are hardy to at least 15°F (–9°C)
Overwintering. Cool, bright, and dry. (See Cool & Bright.)
Propagating. Divide; in the case of the species, start from seed.
Common pest problems. None.
Hardiness varies
Overwintering. Cool or room temperature with sun. (See Sunny & Warm and Cool & Bright.)
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 5°F (–15°C)
Overwintering. Cool, bright, and dry. (See Cool & Bright.)
Propagating. Species are grown easily from seed, the hybrids should be propagated from divisions.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Sunny and warm or dormant in the pot (see here). (See Sunny & Warm.)
Propagating. Cuttings taken early in the season before bud initiation.
Common pest problems. Aphids and whiteflies both love lantanas. (See Specific Pests and Diseases.)
Most are hardy to at least 15°F (–9°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here) — in a greenhouse, our plants generally bloomed in midwinter, an exhilarating and cheery sight. To avoid eliminating blooms, do not prune back before overwintering.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). Allow soil to dry out very well between waterings. Do not prune if you want winter blooms.
Propagating. Cuttings taken early in winter, before bud initiation.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). The habit of malvastrum is open and somewhat rangy — prune lightly to shape, but watch out for those flower buds!
Propagating. Cuttings.
Common pest problems. Aphids seem to find most malvaceous plants delicious. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here); cool temperatures minimize insect infestations. Prune as necessary to keep the plant manageable.
Propagating. Cultivars by cuttings; species by seed, although it may be a year or so before they bloom.
Common pest problems. Aphids, whiteflies. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Warm and sunny. If not kept warm enough, manihot may go dormant, but it will revive with increased light and warmth in spring. Keep it on the dry side all winter. You can let it go dormant and set it in a cooler, darker spot, like the basement, but in this case, make sure it doesn’t ever dry out completely. Do not prune. (See Sunny & Warm and Dark & Damp.)
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). This vigorous plant may benefit from a pruning now and then.
Propagating. Easy to grow from seed.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Prune back hard in the fall.
Propagating. Species are easily grown from seed. The cultivars are trickier and must be vegetatively propagated.
Common pest problems. None that we know of, although situating the plants in a location that is too windy or too sunny can result in damaged foliage. Placement in semi-shade is best in most North American gardens.
Hardiness varies
Overwintering. Warm and sunny (see here); winter temperatures above 40°F (4°C). Many gardeners also have success overwintering dormant bananas in a dark basement; if using this method, be sure to keep the soil dry.
Propagating. Division of pups. Because bananas are monocarpic, the parent plant dies after one full season. In cold climates, this may take more than one calendar year, but in our experience, once a banana has bloomed, the parent plant will not survive long.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Warm and sunny (see here). Prune to shape when necessary.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Easy to keep as houseplants, they’re reasonably happy without large amounts of sunshine. Neoregelias are especially appreciative of visits to the shower. In dry indoor heat, it’s a good idea to keep the plant’s central funnel filled with water. Occasional removal of old leaves is good, but otherwise, no pruning is necessary. (See Sunny & Warm.)
Propagating. Division of offsets.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here).
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Bright, but not too cool. Storage between 50 and 65°F (10–18°C) is best; warmer temperatures will encourage the growth of aphid populations. Water sparingly. Frequent pruning for culinary use and for shaping is an excellent idea. (See Cool & Bright.)
Propagating. Cuttings.
Common pest problems. If this plant is kept too wet or does not receive adequate sunlight, botrytis, mildew, and damping-off are all possibilities.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Any pruning is best done after bloom, in the spring.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). As osteospermums bloom during the winter, refrain from pruning except for removal of spent blooms.
Propagating. Species can be grown easily from seed. The hybrids should be propagated by cuttings.
Common pest problems. If osteospermums experience stressful conditions, aphids may find them attractive. (See Specific Pests and Diseases.)
Hardiness varies
Overwintering. Cool and bright (see here). Dormant types will require little active care. Those that continue to grow through the winter may benefit from a light shearing at some point.
Propagating. This depends on the type. Oxalis species that have a dormant period are best propagated by repotting the corms. Other types can remain in containers and continue to grow even in the winter, given cool and relatively bright conditions. Propagate these species from cuttings.
Common pest problems. None.
Hardiness varies
Overwintering. Cool and bright (see here). Passionflowers require good drainage and thrive on frequent feeding. Because they’re vigorous growers, regular pruning will keep them looking their best.
Propagating. Many of the species can be grown from seed, although this may be challenging. Collect fresh seed and soak it before sowing. Most passionflowers are easily rooted from tip cuttings taken in early spring.
Common pest problems. Whiteflies and spider mites may find these attractive. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright (see here). Water sparingly; remember that the South African winter is a dry one. Keep dead leaves picked off, and trim spent flower clusters as needed.
Propagating. Cuttings.
Common pest problems. During the winter months, geraniums may be troubled by rust; discourage this problem by removing and disposing of infected leaves. Botrytis, which can also be a seasonal issue, will be similarly discouraged by the removal of spent blossoms and the prevalence of good air circulation.
Hardy to at least 20°F (–7°C)
Overwintering. Although pentas bloom and grow best in warm conditions, they will store well in a cool, bright location where they will become dormant. (See Sunny & Warm and Cool & Bright.)
Propagating. Cultivars must be propagated by cuttings.
Common pest problems. Aphids, whiteflies. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Although they benefit from a considerable amount of water when in active growth, we have found that the key to the successful overwintering of phormiums is to keep them dry in cool and bright conditions. Wet and cool conditions can stress them, predisposing them to winter demise. Phormiums should not be pruned; merely remove old leaves as needed. (See Cool & Bright.)
Propagating. Species may be grown from seed, especially if your plant flowers and sets seed. The cultivars are generally produced by division. Newly divided plants will take some time to recover.
Common pest problems. Most problems we have encountered with phormiums stem from over-watering, not pests.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). Cut plants back hard in the fall and repeat as needed.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Prune to shape as desired.
Propagating. Species may be grown from seed. Cultivars are best grown from cuttings.
Common pest problems. None.
Hardy to at least 20°F (–7°C)
Overwintering. Cool and bright (see here). Prune to shape in the fall.
Propagating. Species may be grown from seed. Cultivars should be grown from cuttings.
Common pest problems. Both spider mites and whiteflies adore plumbago; be vigilant. (See Specific Pests and Diseases.)
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here).
Propagating. The bulbs form offsets that are easily divided.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Prune to shape as desired.
Propagating. Species are easily grown from seed, and cultivars should be propagated from cuttings.
Common pest problems. None.
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright. It can also be placed in warmer and sunny conditions, but then it will stay in active growth. In either case, prune back fairly hard to reduce the size of the plant. (See Sunny & Warm and Cool & Bright.)
Propagating. Seeds.
Common pest problems. None.
Hardy to at least –5°F (–20°C)
Overwintering. Cool and bright (see here) — the cooler and brighter, the better. Prune to shape.
Propagating. Cuttings.
Common pest problems. Aphids. Powdery mildew is often a serious problem when overwintering rosemary indoors. The best preventives are good air circulation and cool growing conditions — temperatures between 30 and 40°F (–1–4°C) are ideal. It is also important not to over-water. (See Specific Pests and Diseases.)
Hardiness varies from –25 to 30°F (–32 to –1°C)
Overwintering. Cool and bright (see here). Do not be afraid to prune hard in the fall and when necessary thereafter.
Propagating. Cuttings root rapidly. Species can be grown from seed.
Common pest problems. None.
Hardiness varies
Overwintering. Cool and bright, but some gardeners have successfully overwintered salvias in dark, dry conditions. It is worth experimenting with this if there are no other options. Salvia patens and S. guaranitica can be overwintered as a tuber, in dark and damp conditions. Most salvias should be cut back hard in the fall. (See Cool & Bright and Dark & Dry.)
Propagating. For the most part, the species grow easily from seed; cultivars and selections, from cuttings.
Common pest problems. In greenhouses, aphids are periodically a problem, but this is a good illustration of how a pest issue that is troublesome when plants are confined indoors will generally clear up quickly when the plants are moved outside. (See Specific Pests and Diseases.)
Hardiness varies
Overwintering. Cool and bright (see here). Prune to shape as desired.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here).
Propagating. Division.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 45°F (7°C)
Overwintering. Dark and dry (see here). Sinningia’s preference for dry winters makes it a trouble-free tender perennial to store. We have put the entire pot down in the cellar for the winter and brought it upstairs in the spring, at which point it revived abruptly with light and water. After exposure to a light frost, cut back sinningia stems before storing for the winter.
Propagating. Most species are easily grown from seed and reach flowering size within a year. The mature plants form tubers, which you can separate when they are dormant. Even the florist’s gloxinia is commonly potted up as a tuber in the spring or summer.
Common pest problems. Botrytis can become a problem if conditions are too moist.
Hardiness varies by species
Overwintering. Cool and bright (see here). Prune to shape as desired.
Propagating. Species, seeds; cultivars, cuttings.
Common pest problems. Few pests want to mess with solanums.
Hardy to at least 45°F (7°C)
Overwintering. Warm and sunny (see here), either as a whole plant or by cuttings. Particularly when grown indoors, coleus will require occasional pruning — do not be afraid to cut off quite a bit to make plants more manageable.
Propagating. Cuttings.
Common pest problems. Aphids, scale, whiteflies. (See Specific Pests and Diseases.)
Hardiness varies by species
Overwintering. Warm and sunny (see here). Cut back before moving plant inside.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Individual species vary in their preferred temperature ranges; for instance, Thunbergia alata will thrive in bright, relatively cool environments, as low as 40°F (4°C); T. mysorensis will not. T. grandiflora grows vigorously in a range of conditions from sunny to shaded. It also likes cool temperatures, but is fine with considerable shade; T. mysorensis should be kept warm and sunny. Cut plants back hard before moving them indoors in the fall. (See Sunny & Warm and Cool & Bright.)
Propagating. Some species, such as Thunbergia alata, can be started from seed. Others may be easier to grow from cuttings.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Cool and bright is preferred, although warmer and sunny also works (see here and here). Cut plants back hard in the fall before moving indoors.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 5°F (–15°C)
Overwintering. Cool and bright (see here) really essential.
Propagating. Cuttings.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright (see here). Prune to shape as desired.
Propagating. Just like its cousin Asclepias syriaca, the common roadside milkweed, pollinated Tweedia caerulea flowers turn into leathery pods full of silk-tasseled seeds; these germinate easily.
Common pest problems. Aphids. (See Specific Pests and Diseases.)
Hardy to at least 25°F (–4°C)
Overwintering. Cool and bright (see here). Water sparingly. Remove old leaves, but do not trim.
Propagating. Seeds.
Common pest problems. None.
Hardy to at least 35°F (2°C)
Overwintering. Cool and bright for both species (see here). Veltheimia capensis will recuperate after bloom through the spring and much of the summer, and should be kept dry during this period. V. bracteata is in active growth all year.
Propagating. Division of bulb offsets or by seed, if flowers are left to set them.
Common pest problems. None.
Hardy to at least 45°F (7°C)
Overwintering. Warm, sunny, and humid. Trim off old leaves as the plant becomes dormant. Tubers can also be stored in dark and moist conditions, just like cannas. Keep the tuber cool but not cold — above 40°F (4°C). (See Sunny & Warm and Dark & Damp.)
Propagating. Division of offsets.
Common pest problems. The greatest challenge to cultivating these is providing adequate warmth and humidity. Otherwise, plants will sulk, leading to other complications, such as botrytis.