The forecast for July is continuing to look promising with occasional rain, wind or thunderstorms depending on where you live but on the whole temperatures will remain above average with dry and fine weather likely for most of the time. This dry weather means weeds are easier to control, just hoe off & they will soon die, but there is a need to keep on top of feeding & watering if you want your tubs & baskets to keep looking good. Keep on top of garden chores such as cutting back plants that have finished flowering & make sure drains are clear & guttering free of debris as sudden thunderstorms can create localised flooding.
Ensure you are ready for the sunshine by stocking up on barbecue essentials & be ready to take in your parasol & garden cushions when rain is due or get a garden store so they are always close at hand. If you want some great barbecuing tips & recipes check out our blog on Barbecuing.
Planting & Sowing
- Take cuttings from summer container plants for next year & also any pinks or carnations that have become leggy.
- A good time to sow early flowering perennials such as Delphinium, Lupin & Bellis.
- Buy and plant autumn flowering bulbs such as Colchicum for late colour. This late flowering bulb resembles a crocus and prefers well drained soil. It can be naturalised under trees in bold drifts - plant with the base of the bulb at about 13cm (5") below the soil surface.
- Propagate shrubs such as Choisya, Hydrangea and Philadelphus by taking semi-ripe cuttings & potting them in gritty compost. Place in a cold frame, propagator or put a plastic bag over the pot & secure with an elastic band, leaving space above the cutting.
- July is also the perfect month for sowing seeds of biennial plants such as honesty, sweet rocket, wallflowers, Icelandic poppies, foxgloves, sweet williams, pansies and forget-me-nots. Keep the seeds nice and damp for the best results.
- Sow salads and spinach and container sown leeks and brassicas for winter and early spring crops - see our ‘grow your own' article.
- Replant bearded iris - Iris germanica flower profusely in June and then die off above ground. If they have been in the same place for about five years, they need to be dug up and the rhizomes need to be divided and planted anew if you want to see profuse flowering next year. These irises like a dry and sunny spot. Mix some extra lime into the soil. The tops of the rhizome should protrude slightly above the soil. Plant them in a north-south direction.
- Cut back side shoots of gooseberries, white & red-currants.
- When hardy geraniums have finished flowering they can be cut back which will neaten the plant & encourage new foliage & flowers.
- Shrubs like Kolkwitzia, Weigela and mock orange (Philadelphus coronarius) will have finished flowering at the end of this month and can then be pruned straightaway. Prune just above the new shoots or cut the branches down to just above ground level.
- Wisteria forms many searching shoots which may extend to spots where you don't want them to be. Cut them back to around five or six buds of the main stem.
- Summer raspberries will usually have finished by the end of July. All the stems which have borne fruit can then be cut back as far as possible. Tie good new shoots (no more than fifteen per linear metre), cut back all other shoots.
- Cut away excessive foliage on grapes which can impede the formation of fruit and cut back shoots which have overshot.
- Hedges can still be trimmed. The more you trim, the denser a hedge becomes. Of course this works best with a fast-growing hedge.
- Take cuttings of evergreens such as rhododendrons, camellias and heathers.
- Remove faded flowering spikes from perenials like foxgloves, Verbascum & delphinium. Deadhead flowering bedding plants & roses to prolong flowering.
- Thin out overcrowded apples, pears & plums to get fewer, but better quality, fruits. Then prune established damson, cherry & plum trees after they have cropped.
- Prune box hedging & topiary at the end of the month.
- Keep on top of watering, plants in grow bags such as tomatoes, newly planted trees and newly turfed or sown lawns all need extra care during the hot weather. Water Camellias in containers to ensure good bud formation for next year. You can also avoid mildew on wall trained roses and honeysuckle by extra watering.
- Keep your tubs, pots and hanging baskets looking good by regular watering and feeding with tomato fertiliser to promote flowering.
- Various perennials like lupins, Delphiniums, Salvia x superba and Achillea taygetea will give a second flowering under good conditions if they are cut back after the first flowering. Often this will be in July.
- Whilst deadheading & tidying don’t forget to collect any seeds that have ripened from annuals that you would like to grow again next year e.g. Nigella, marigold. Poppies.
- Net soft fruits to protect them from birds.
- Spray your plants with fungicide if they are suffering from powdery mildew & this can also be used to prevent blight on potatoes & tomatoes.
- Apply a summer feed if your lawn is not growing vigorously. If you do need to water it is best done occasionally with a good drenching rather than little & often. However if there is a drought avoid the use of high nitrogen fertilisers which will try to make the grass grow at the expense of the roots & raise your blades when cutting the lawn.
- Keep harvesting your crops such as beans & courgettes at regular intervals to keep them producing.
- Some plants can easily develop wild shoots. New shoots can then emerge from the roots anywhere nearby. Well-known examples are Staghorn Sumac, Kerria, raspberry, blackberry, sea buckthorn, all sorts of bamboos and Campsis.
- Keep on deadheading roses to prolong flowering.
- Keep greenhouses well-ventilated and shaded to prevent sun scorch & overheating of your plants.
- If the water lilies develop too many leaves and hardly flower, it is time to divide their rhizomes and replant them.
- Leave plants that you remove from the pond lying on the side for a while so that any small creatures in them can make their back to the water.
- To keep the pond healthy it is essential to maintain some open water.
- If there is enough oxygen in the pond water, it will not become acidic. The best thing to do is to ensure that there are enough oxygenators (underwater plants) in the pond. By keeping the water healthy in this way your pond plants will grow better and fish will remain healthier. Alternatively, running a fountain helps increase oxygenation.
- The floating and underwater plants will grow vigorously. There may be a need to thin them regularly.
- The same applies to filament algae that you remove from the pond (which may also be a regular chore).
- In warm weather you need to top up your pond regularly, since the water evaporates quickly and the water level will drop even more rapidly if there are a lot of marginal plants in the pond water. If possible, use mains water for this. Ensure that the water jet never hits the pond directly and hard if there are fish in the pond.