Trees and shrubs

Planting and moving

Elaeagnus ebbingei 'Limelight'Evergreens

In cooler areas, and earlier in the month, you can still move and plant evergreen trees and shrubs (see Elaeagnus ebbingei 'Limelight', left), provided the soil is not waterlogged. They are best moved or planted once actively growing and when there is less risk of cold weather.


In colder areas, you can also still plant container-grown deciduous hedging plants, shrubs, trees and climbers. Stakes and rabbit guards should be put in place at the time of planting to prevent damage to the rootball and bark.

Remember that watering and establishment may be problematic for large plants as the weather gets warmer and dryer, and you may be better delaying planting them until October.

mulching a roseFeeding and mulching

Mulch rose and shrub beds with a 5-8cm (2-3in) layer of organic matter. This will help retain moisture during dry spells, reduce weed build-up and over time improve soil structure. Pay particular attention to mulching around rhododendrons, azaleas and camellias, as flowering is impaired if they are allowed to dry out during late summer.

Feed trees, shrubs and hedges with a balanced fertiliser (such as Growmore or blood, fish and bone), sprinkling it over the root area before hoeing into the soil surface. This will particularly benefit young, weak, damaged or heavily pruned plants.

Pruning and training

pruning cornusWinter-stemmed shrubs such as Salix and Cornus can still be cut back at the beginning of the month. Prune back hard all the previous year's growth to within 1-2cm (0.5-0.75in) of the framework.

Other shrubs that are routinely stooled (cut back hard) in spring, to keep their larger or more brightly coloured juvenile foliage, such as the smoke bush (Cotinus) and elders (Sambucus), can be cut back this month. You can leave a couple of branches un-pruned if you are reluctant to lose all the height gained last year.

Delay pruning spring-flowering shrubs such as Forsythia and Chaenomeles until after they have finished flowering, otherwise this year's display will be lost.

Remove any frost damaged shoots from evergreens damaged by earlier cold weather.

Remove any reverted green shoots on hardy variegated evergreens, to prevent reversion taking over.

Lightly cut back lavenders to prevent them getting too leggy and woody. Treat Helichrysum (curry plant) and Santolina (cotton lavender) similarly.

Loosen any tree ties that are digging into the bark, or could do so soon as the trunk girth expands.

Twining climbers (such as honeysuckle and clematis) need regular tying in and twining around their supports.

Tie in climbing and rambling roses as near to horizontal as possible. This will restrict sap flow, causing more sideshoots to grow along the length of stem, and so producing more flowers.


layering sagePropagation

Layering is a good way to propagate climbers and lax-stemmed shrubs. Layers should root by next spring, especially if attention to watering is given during dry weather. Try with PhiladelphusForsythiaHydrangea and Lonicera. (See sage layering right).

Check hardwood cuttings taken last year. They may need planting out or potting on.

Take cuttings of your favourite conifers.

Pest and disease watch

bracket fungiBracket fungus (left) on trees is more visible at this time of year. If the tree is in poor health it is worth calling in a tree surgeon for a professional opinion.

Phytophthora root rots can cause die back on mature trees and shrubs. Wet winter weather and poorly drained soils are likely to encourage this problem on susceptible woody plants.

Check for damage or cankers on deciduous trees.

Put rabbit guards around newly planted trees and shrubs to protect the bark.

Avoid planting new roses in areas where roses were previously growing otherwise the new plants may suffer from rose replant disease.

Inspect sick-looking box and holly trees for signs of blight.

Be aware that insects emerge as temperatures rise. Caterpillars, aphids, and other fly pests may all become problematic during mild spells. Early infestations can often be managed by hand removal, making insecticides unnecessary.


Feed large aquatic plants (if their growth or flowering last year indicated they need it) by inserting special aquatic slow-release fertiliser tablets well below soil level around the base of the plant. Waterlilies are also big feeders. Feed any plants not being divided.

Continue dividing or cutting back marginal and bog garden plants if overcrowded.

Divide and replant waterlilies once they show signs of growth.

Contain vigorous pond perennials by planting them in aquatic plant baskets and topping with a layer of gravel to prevent fish stirring up the compost.

Small plants in baskets can be raised up on bricks when first introduced then slowly lowered to the bottom of the pond as the plants increase in size.

Tidy up plants in the bog garden, and mulch with composted bark (or similar - avoiding manure if there is a chance that water may run off into a pond).

pond algaeTroubleshooting

Don't worry if the water in your pond suddenly turns from clear to greenish, it's natural for a certain amount of algae to grow in the spring as life begins to stir after the winter. If the problem persists for more than a few weeks, consider adding more oxygenating plants to help clear the water.