Jobs in July
Sowing and planting
Autumn-flowering bulbs, such as autumn crocuses, Colchicum, Sternbergia, Amaryllis and Nerine, can be planted now.
Some seeds are best planted just after collection, and others may need specific climatic conditions to break dormancy (e.g. some alpines). If unsure, then sow seeds in ‘batches’, i.e. one immediately after collecting, one in winter, and one in the following spring.
Cutting back, pruning and dividing
Cutting back plants in baskets followed by feeding can encourage new growth and help revive tired displays.
Cut back delphiniums and geraniums after the first flush of flowers to encourage a second flowering period. Feed after cutting them back.
Deadhead flower borders regularly to prolong flowering. Disbud and dead-head dahlias if growing for large blooms. Leave roses that produce attractive hips.
Divide clumps of bearded iris.
Plants with a carpet-like growth habit, e.g. some alpines, can become patchy, with central areas dying off. These patches can be in-filled with gritty compost, to encourage re-growth.
Propagation
Take cuttings of patio and container plants ready for next year.
Pinks and carnations that have become leggy, can be propagated by layering or by cuttings. Propagation can improve the appearance of untidy clumps.
General maintenance
Prop up tall perennials such as lupins, delphiniums and gladioli if staking was neglected earlier in the season.
Liquid feed containerised plants and keep well watered in dry spells.
Some late-flowering border perennials may benefit from a quick-acting feed before they come into bloom, especially if the soil is not very fertile.
Mulching borders can help retain moisture, and keep down the weeds – this will save a lot of work. A really thick layer of mulch (5-7.5cm/2-3in all over) works best.
Most perennial weeds are best dealt with in the summer when the weeds are in active growth. Digging out often works, but applying a weedkiller can be more practical, particularly for large areas.
Planning ahead
Start collecting seed from plants you want to grow next year, especially annuals such as Calendula, poppy and love-in-a-mist.
Pest and disease watch
Inspect lilies for the scarlet lily beetle whose larvae can strip plants in days.
Vine weevils can also be a problem at this time of year.
Small holes and tears in new foliage of ornamentals such as Caryopteris, Fuchsia and Dahlia are most likely caused by capsid bug damage.
Watch out for aphids (greeenfly and blackfly) on stems and leaves of young shoots.
Sudden collapse of apparently healthy clematis, especially the large-flowered cultivars, could indicate clematis wilt.
In dry weather powdery mildew can play havoc with plants such as clematis, roses and Lonicera.
Look out for and treat black spot on roses and scab on Pyracantha.
Beer Traps for Slugs and Snails.
If you like I have an infestation like of slugs and snails in your garden then you can solve it without the use of slug pellets. Like many of us they like beer, so all you have to do is leave out a dish (1inch in depth of beer) in the evening with a lip about three inches from the ground as once they go in you don’t want them coming back out. There attracted to the smell and drown quite happily in it. If you have a dog like I do then make sure they do not drink from it as it will not be pleasant for them. Always check your dish the following day to dispose of its contents.
To make the most of water it pays to use it economically. It helps to understand the needs of plants and use techniques to prevent water loss from both plants and soil.
When to water
Gardeners can inspect the soil at a spade’s depth. If the soil feels damp there is unlikely to be any need to water, but if it is dry, then watering is probably required for some plants.
Gardeners should be aware that clay soils can feel damp even when all available water has been used and that sand soils can feel dry even if some water is available. The only way round this is to develop experience in matching the observed state of an individual garden’s soil to the growth rate of the plants. Wilting is usually preceded by changes in leaf position and darkening of leaf colour.
How to water
It is better to water the garden before drought really sets in, to keep the soil moisture levels even and avoid soil moisture deficits building up.
Once drought has set in, it is futile to try and remedy this by light watering over a wide area. Light watering may encourage surface rather than deep roots, leaving plants more susceptible to drought. Instead, make a single thorough watering of the plants that are suffering. Try to water in the cool of the evening or the very early morning so that less water is lost immediately to evaporation.
Watering should never be carried out where drainage is poor, as adding water will do more harm than good, roots being very susceptible to airless conditions, particularly when the soil is warm in summer.
How much water to apply
Light sandy soils need watering more frequently than heavy soils, but less water can be applied at each watering. Heavier, clay-based soils can be watered less frequently, but need heavier applications of water because they hold more water within their structure.
A clay soil in which plants are wilting might need 81 litres per sq metre (17.5 gallons per 10 sq ft) and a sandy soil in which plants are wilting might need 60 litres per sq metre (12.2 gallons per 10 sq ft).
In practice, gardeners are unlikely to regularly let the soil get so dry that plants are wilting, so less water is required. Water can also be saved by applying it to the base of the plant rather than over a wide area. As a general guide, up to 24 litres per sq metre (5.2 gallons per 10 sq ft) every seven to 10 days will be sufficient to maintain plant growth.
Methods of watering
Sprinklers: These have only limited use in gardens, mainly to water the lawn where this is essential, and to raise the moisture level of unplanted areas.
Hoses and watering cans: Most garden watering should be aimed specifically at the stem bases beneath the foliage canopy, leaving the surrounding soil dry. This helps to limit weed problems and ensures all the water goes where it is needed.
Seep hoses: These hoses or pipes with holes in them deliver water accurately to established plants and plants in rows. They can be hidden beneath soil or mulch, which also avoids evaporation losses. They work best on heavy soil where the water spreads further sideways as it sinks than on lighter soils.
Automated irrigation systems: To save time and labour, watering cans and hoses can be replaced by drip or trickle irrigation systems. Only the root zone or top 60cm (2ft) of soil should be wetted – water that penetrates deeper will be inaccessible to most plant roots. Suppliers can advise on installation of these systems. See for example, Access Irrigation, Garden Systems, or LBS Horticulture.
Tips for economical watering
Established trees and shrubs do not generally need watering, as they have such wide-ranging roots that they are drought-proof. But their growth may be improved by watering when they are under drought-stress.
Trees and shrubs planted less than five years ago have increased water requirements and may suffer drought-stress without watering.
Newly sown or newly planted areas are very vulnerable to water-stress, and watering these should be high priority.
Herbaceous perennials often need watering to boost their performance in hot, dry spells. Plant choice is crucial if you want to achieve a drought-proof border. See our advice on drought-resistant plants for more on plant choice.
Edible produce yields and quality are greatly improved by watering at times when drought stress would affect the part of the plant that is gathered. Leafy crops such as lettuce and spinach should never be short of water. Onions require little or no watering. Most other crops need watering at sowing and transplanting time, and then again as the fruits, roots or tubers are developing. It is also a good idea to give a single, thorough watering about two weeks before harvest.
Lawns require great quantities of water for thorough irrigation, and this is a questionable use of a scarce resource for any other than high quality lawns or sports turf. Instead of watering in dry periods, feed the lawn well and mow less closely and less frequently. Brown patches usually recover when the autumn rains return.
Mulching with a layer of organic matter or gravel at least 5cm (2in) thick, or using opaque mulching sheets, reduces moisture loss from the upper layers of the soil. This may amount to as much as the equivalent of 2cm (0.75in) of rain.
Removing weeds is vital, as weeds use up valuable soil moisture reserves.
Planting new plants between autumn and spring gives them the best chance of growing roots before dry weather begins.
