Water, deadhead, collect seeds and care for your lawn as the warm weather continues
✔ Watering the garden is essential at this time of year but it can be costly to your wallet and also to plants if you don’t get it right. Some gardeners find it quite pleasant to water in the evening after dinner but wet leaves during the night can cause fungal diseases on many plants, particularly roses. Early morning is best so moisture can be absorbed into the soil before the sun dries it out.
✔ Deadheading spent blooms is a great way to encourage plants into a second bout of flowering. However leaving some of the flowers to produce seed is even better as you can store it over winter to grow new plants for next season. Seed must be dry so don’t collect it on a rainy day, and store in a paper bag or envelope (not plastic) somewhere cool and dry. Don’t forget to label with plant name (even the best gardeners sometimes do this).
✔ Flowering annuals and perennials that grow easily from seed include aquilegia, Californian lilac, cosmos, delphinium, dietes, helleborus, honesty, libertia, lupin, nasturtium, poppy, rengarenga lily, snapdragon, sunflower and sweet peas.
✔ Tall perennials (lilies, dahlias, hollyhocks, delphiniums, salvia) can flop very quickly when the wind whips up so stake them before that happens. There are some very cool-looking plant supports available now that can add a valuable structural element to garden beds.
✔ To keep lawns looking healthy in mid summer it’s important to protect the roots of grass plants from the heat. Scalping the lawn too closely will expose the roots to the hot sun but if you raise mower blades a little higher they’ll have more shade. Don’t give the lawn too much fertiliser either as it can make grass soft and lanky and therefore more susceptible to drought.
✔ Trim English (Lavandula angustifolia) and French lavenders (Lavandula stoechas) to the top of the foliage but not into old wood. Wait until March to cut back larger Lavandula dentata bushes.
✔ Cut back roses and feed with a rose fertiliser to encourage more flowers.
✔ On the subject of roses, some gardeners say that planting scented geraniums around plants will repel pests and fungal diseases. Worth a try as they look pretty together anyway.
✔ Warm air encourages white fly, aphids and other sap-sucking insects that can infest ornamental shrubs and trees. As well as thinning out branches to increase air circulation in shrubs and trees try spraying leaves weekly with organic Neem oil.
✔ Plant salvias and zinnias for late summer colour.
✔ Add water-retaining crystals to potting mix if your containers are in a hot, sunny spot. This is especially important for hanging baskets and water-hungry plants such as flowering annuals and vegetables. In hot summer weather they will need watering every day (less for succulents).
✔ In warmer areas mophead hydrangeas (Hydrangea macrophylla varieties) can be pruned back after flowering any time from now onwards. Shorten stems to just above an upper pair of fat buds, don’t cut down to the ground or you’ll get no flowers next year.
✔ If you’d love more hydrangeas in the garden save some stems from your pruning to propagate as cuttings for more plants. They usually take quite easily if you pop woody cuttings into a mix of potting compost and crushed pumice. Keep mix moist and remove all but two or three sets of leaves to encourage root growth.
✔ Wait until spring to prune your hydrangeas if you live in a frosty region.
Words by: Carol Bucknell
Photography by: Sally Tagg