GARDENING TIPS FOR JULY February 25, 2008
(Compiled by Lyn McCallum)
Those of you who have boreholes with automatic irrigation systems are reminded to make the necessary adjustments, so that they do not come on during or just after rain.
Remember that spite of good rains, there are some parts of the garden that can remain relatively dry. Check beds in the shadow of hedges, under trees with dense canopies, on the south and east side of high walls and under the eaves of buildings. These areas may not be getting sufficient water.
Mulching in winter helps the soil from becoming compacted by heavy rain, as well as helping to suppress any weed growth. Keep the mulch away from the stems of plants to prevent rotting. Mulch should be at least 10 to 15mm deep for annuals and perennials, but can be as deep as 50mm for trees and shrubs. Coarse compost, well rotted kraal manure, bark chips or milled bark, pine needles (for acid loving plants) and straw all make a good mulch.
Deadhead your annuals and winter flowering perennials regularly to encourage more flowering. Sweet peas and Iceland poppies will further benefit from having their flowers picked regularly for the vase. Feed at least once a month with a liquid foliar feed or soil drench such as Nitrosol, Organiksol, or Seagro if the weather is fine. During wet spells, sprinkle Bounce Back, Rapid Raiser or 3.1.5 Organic lightly between the plants, and fork into the soil gently, but be careful of 3.1.5 Organic. It is very strong and can burn. Weed between the plants when necessary and keep a watchful eye out for those persistent slugs and snails. Don’t forget to mulch.
Many of the spring flowering bulbs are starting to come up, and snowdrops (Leucojum) and some narcissi are beginning to flower. Feed regularly with Hadeco bulb food, and keep on removing weeds, as well as slugs and snails. Mulch!
July is the month to plant Lilium bulbs. These bulbs require a cool, moist place to grow, with well-drained soil that has been dug over lightly to a depth of 20 cm. Incorporate a generous amount of well-decomposed compost or leaf mould and plant the larger bulbs in groups at a depth of 10 cm. The smaller varieties should be planted, also in groups, at about 7 – 10 cm depth. Once the bulbs start to sprout, mulch with a good compost and ensure that they do not dry out or become waterlogged. Liliums prefer their bulbs to be in cool soil, but they do like their leaves and flowers to be in the sun, so choose where to plant the bulbs with this in mind. They can also be planted in pots, one large bulb or 3 smaller bulbs per pot. Deep containers are best. The rim of the container must be at least 3 cm away from the bulbs, with 10 cm of soil below the bulbs.
Impatiens don’t like cold, wet, windy weather! However, they can and do still grow well in a sheltered spot, and will brighten up the winter garden with a welcome show of colour. Remember to water with a solution of Condies Crystals 1 teaspoon in 5 litres of water to prevent fungal problems. Cut them back as soon as the stems become “leggy” (yes, even if they still have flowers!) and dig in a handful of Rapid Raiser and compost, which will also loosen the soil around the plants.
July is the latest that summer flowering shrubs can be pruned. Leave it any later, and you will interfere with the new growth that starts appearing later on this month and in August and September. Winter flowering shrubs such as Ribbon Bush (Hypoestes aristata), Salvias, Wild Dagga (Leonotis leonuris) and Barleria can be pruned as soon as they have finished flowering. Coprosma, eugenias and myrtles, which are evergreen, should be trimmed now to maintain their shape.
Camellias and azaleas should be flowering now, giving a colourful lift to dark, damp winter days. Remember not to feed these shrubs until their flowering period is over.
Compost heaps should be covered to prevent them from becoming waterlogged during the rainy periods. Regular turning – at least every 6-7 weeks- will speed up the decomposition process. Wood ash from your winter fires can be added to your compost heap, but not coal or anthracite ash.
Roses should not be pruned before the end of July. If you are unsure of how to go about pruning, contact Starke Aires in Rosebank, who normally have a rose pruning demonstration during July.
Indoor pot plants are adversely affected by the lack of humidity in heated rooms. To compensate for this, stand pots on pebbles in a tray of water, or place a saucer of water near the pots. Don’t overwater your indoor plants during winter!
It is a good idea to check the drainage of all your outdoor pots and containers regularly. Most plants hate being waterlogged, which damages the fine root hairs that take up the moisture and nutrients needed by the plant for growth. Don’t make the mistake of assuming that a plant is drooping because it is not getting enough water! At this time of the year, it could quite easily be dying from too much water due to poor drainage. Ensure that the drainage holes of the pots are not blocked, and stand them on pot feet, bricks or anything that will raise the pot off the ground by at least 2cm. If the plant has become waterlogged and is showing signs of dying, repot it as soon as possible into fresh well draining potting mix such as Master Patio Mix, into a pot with good drainage. Cut the plant back lightly and hope for the best!
Plants in pots and hanging baskets need feeding more often than those planted out in flowerbeds, as the nutrients are leached out by continual rain and watering. A feed of Nitrosol, or Seagro or other water soluble plant food should ideally be given every 2 to 3 weeks. Once the plants have reached maturity, use a plant food rich in potash – Organiksol- to encourage flowering. Don’t forget to deadhead regularly to encourage and prolong flowering.
Aloes and most other succulents don’t like too much rain. Most of these plants come from desert or semi desert regions and too much water will make them more susceptible to diseases and could even cause their roots to rot. If necessary move pots with these plants to a dry spot in your garden for the duration of the winter.
Continue to feed your winter vegetable patch with a suitable food – see June Tips. Mulching will help the soil from compacting and will also keep down weed growth. Harvest peas and broad beans regularly to encourage further pod formation. Don’t forget to keep a wary eye out for slugs, snails and caterpillars.
