PLANTING TIMES AND METHODS

The recommended planting methods for different types of plants are explained below. Where a plant has special requirements that differ from this, it is detailed in the information for that module and the general information at the start of that module’s chapter.

Planting trees and shrubs

Check the plant before you buy it: you want healthy stems, branches and leaves, but also a good rootball. The plant should be well-rooted within its pot, with roots to the edge and bottom of the pot. If there is lots of fresh compost around the edge of a rootball that’s smaller than the pot, it’s been recently potted-on and you are paying more money for a small plant in a big pot. Conversely, it could be root- bound, with its roots wound round and round inside the pot with hardly any compost. Plants like this should also be avoided, but if you have no choice you can tease out some of the roots before planting.

Dig your planting hole at least twice the size of the pot your tree/shrub is in, and make sure the base and sides are not compacted. Mycorrhizal fungi can help your tree/shrub get off to a better start. It’s available in good garden centres as ‘Rootgrow’: follow the instructions on the pack.

Plant your tree/shrub so that the top of the root flare is at soil level. Firm in the soil around the rootball well, and water (at least a watering can’s worth). Make sure no mulch is touching the stem as it may cause it to rot. Keep it well watered for a few weeks, longer if the weather is particularly dry. Stake it if necessary (see p. 160).

Planting herbaceous perennials

Perennials can be planted in spring or autumn, when the ground is (still) warm and there is usually enough rain to keep the soil moisture levels high enough for the plants to establish. Dig a hole about half as big again as the size of the pot, and plant so the top of the rootball is at soil level. Fill in the soil around it firmly: there must be good contact between the rootball and the soil or it will be unable to take up water. A tug on the stems shouldn’t dislodge the plant. Keep it well watered until it’s established. Stake it if necessary (p. 160).

Pot sizes, divided clumps

Smaller plants take longer to grow and fill out their allotted space, it will be longer before you can start using them, and they need more watering until they establish. Ideally, buy herbaceous perennials in 1, 1.5 or 2 litre pots. These are not so small that they will take ages to get going, or so big that they are really expensive.

You may be able to divide clumps of herbaceous perennials from friends’ plants. Do this in spring or autumn. Dig up the plant and, using a spade or two forks, cut or pull off a clump. Make sure it has a reasonably equal stem to root ratio (err on the side of more roots). Wrap it in a plastic bag to conserve moisture, and plant as soon as possible. Check the rootball for roots of perennial weeds before you plant it and water well.

Planting bulbs

Plant bulbs in autumn. Dig a hole three times the size of the bulb deep. Put the bulb in with the root plate at the bottom (pointy bit upwards), and fill in the hole firmly.

Planting perennials by plunging pots

Frost-tender perennials such as dahlias and pelargoniums need protection until all risk of frost has passed, and are therefore not usually planted out into the garden until May/June. They can be plunged into the soil in their pots so they’re easier to bring indoors in the winter. Porous terracotta is better than plastic, but they’ll still need more watering.

This method can also be used for invasive plants such as mint. In this case, leave the lip of the pot protruding above soil level between 2 and 5cm to make it easier to snip off the creeping stolons as they grow over the edge.

Planting out plugs of annual plants

If you’ve bought plug plants, plant them out as soon as you can. If you’ve sown your own, they’re ready to plant out when the roots start coming out of the bottom of the module tray.

Push the plugs up and out of the tray from underneath; never pull the delicate main stem. Plant and firm in gently to ensure good contact between the rootball and the soil. A tug on the leaves should not dislodge the rootball. Don’t press down directly around the base of the stem as this may break the roots off. Water well after planting and until established.