Weather in July tends to be very hot. Make sure plants are well watered, especially trees and shrubs that were planted in autumn or winter. The best time to water is either early morning or late evening. This way there will be less water evaporation. It is better to water your plants thoroughly but two to three times a week rather than less but every day.
If you are thinking about installing an irrigation system, the leaky hose system is very efficient as the water leaks around the roots of the plants where it is required, reducing water loss through evaporation.
PESTS & DISEASES:
The warm, moist weather at this time of the year is perfect for pests and diseases to spread. Keep and eye out for black fly, green fly and aphids. To control pests use an approved pesticide such as Provado. The better way to control pests is by having a diversity of planting that encourages beneficial wildlife into the garden that will feast on these pests.
Pick the larvae of scarlet lily beetle and destroy and the adults need to be crushed.
Keep an eye out for disease such as black spot, rust and mildew. With disease prevention is better than cure. Mildew takes hold in drier conditions so make sure moisture levels are right in the garden and plants are not drying out. Additional control is through an approved fungicide.
Black spot should be sprayed with an approved fungicide. Better to do this early before the disease gets a hold.
Rust often appears on plants that are deficient of potash. Feeding with a rose fertilizer will help reduce this.
Cut out infected parts of plants and dispose or burn. DO NOT put in the compost bin
Lawns tend to start going brown at this time of the year. Do not worry, lawns are very good at regenerating when the weather cools. The grass will start greening up when the rains start.
Do not cut lawns too short as this only encourages rapid growth. During dry weather it is best to set the lawn mower a little higher and mow less. It’s better to leave the grass a little longer.
Newly laid lawns must be kept watered. If they are not the, the turf will shrink and the edges will start to curl. You will never get them down flat again.
Make sure you continue to deadhead early flowering plants. Some of these may even give you a second flush of colour.
Continue to deadhead your bedding plants such as geraniums and petunias. This will encourage the plant to produce more flower buds.
Group 2 clematis, which are the beautiful big flowering ones, should be pruned in the middle of July.
Cut back hardy geraniums to ground level after their first flush of flowers, this will encourage new leaves and flowers later in the season.
Prolong Sweet Pea flowering by watering, mulching and dead heading.
Deadhead roses, bedding plants and repeat flowering perennials.
Philadelphus, Weigela and other early summer flowering shrubs should be pruned
Any trees or shrubs that are producing suckers, should have these removed cleanly to conserve the plants energy.
Oriental poppies can be cut down to ground level if the flowers are spent.
Delphinium stalks where the flowers have died, can be cut down. This will encourage new shoots.
Aquilegias will also have faded. If you are not saving the seed, these can be cut down.
Deadhead roses, snipping just below the spent flower head. This will encourage more buds on repeat flowering roses
Evergreen hedges and conifer hedges should be trimmed. Remember to cut them on a batter so that the lower part of the hedge gets sun and can photosynthesis. This way the lower part of the hedge will remain as healthy as the top.
Feed dahlias and cannas fortnightly with a high potassium fertilizer such as tomato feed.
If bearded iris are not producing as many blooms, divide them and replant the young sections 30cm apart. Remember the tubers need to bake in the sun so plant then so that they are only just sitting into the soil.
Autumn flowering bulbs can be planted now to give a display from September through to October and possibly even November.
RUNWAY PLANTS FOR JULY
Cotinus coggygria ‘Royal Purple’
Hebe ‘Midsummer Beauty’
Lavandula angustifolia ‘Hidcote’
Lavandula ‘Imperial Gem’
Spirea japonica ‘Anthony Waterer’
Spirea japonica ‘Goldflame’
Rosa ‘Pierre de Ronsard’
Rosa ‘Gertrude Jekyll’
Rosa ‘Generous Gardener’
Clematis ‘Jackmanii Superba’
Clematis ‘Samaritan Jo’
Clematis texensis ‘Princess Diana’
Jasminum officinale ‘Clotted Cream’
Schizophragma hydrangeoides ‘Rosea’
Amsonia ‘Blue Star’
Astrantia major ‘Hadspen Blood’
Astrantia major ‘Roma’
Ceanothus ‘Puget Blue’
Cleome hassleriana ‘Colour Fountain’
Cosmos bipinnatus Sensation Series
Digitalis x mertonensis
Digitalis parviflora ‘Milk Chocolate’
Geum ‘Prinses Juliana’
Geum ‘Totally Tangerine’
Helenium ‘Moerheim Beauty’
Kniphofia ‘Percy’s Pride’
Nepeta ‘Six Hills Giant’
Salvia nemerosa ‘Caradonna’
Veronicastrum virginicum ‘Fascination’
BULBS & TUBERS
Dahlia ‘Arabian Knight’
Dahlia ‘Bishop of Llandaff’