Spring is traditionally seen as the season for harvesting herbs and veggies, however there are a variety of these food sources that are at their peak for harvesting during our warm summer spells.
Summer is the time to sow and reap carrots, beetroots, beans, pumpkin, marrows, cucumbers, rocket and radishes for example. For tomatoes, eggplant, chillies, green peppers and lettuce, it is easier to sow the seeds into seed trays and wait until they germinate before you plant them into the beds, or even simpler, buy already grown seedlings from your nursery. Putting a thin layer of straw over the sown seeds will help prevent the beds from drying out in the warm weather.
Summer is a good time for herbs such as mint, sweet basil, coriander, dill and oregano. You can also plant herbs that your pets will love, such as dog grass, catnip and borage. To keep the herbs growing well, pick them regularly and feed them twice a month with a liquid fertiliser at half the strength.
As summer proceeds, the suns rays become more harsh and you should therefore protect many of your sensitive plants and bonsai from the sun and wind (especially in the Western Cape).
Remember to adjust your irrigation program for the summer period, taking into consideration the rainfall volume for your area. In the winter rainfall areas the irrigation should be set to water at least 3 times a week for minimum 30 mins on each station, while in summer rainfall areas the irrigation program can be set to water once a week. Test your soil moisture content by digging down to about 20cm below the surface, if your soil is not moist at this level then increase your watering times. If it is damp from the surface down to 20cm below, then switch your irrigation system off or decrease the watering times accordingly.
You will also need to water your bonsai more frequently due to the higher temperatures and wind. Maple bonsai are very sensitive and their leaves can dry out and look scorched. Mist spray the tropical and sub-tropical trees such as Figs, Bougainvilleas, Brush Cherries and the White stinkwood/Chinese Hackberry. Feed the flowering and fruiting bonsai with Nitrosol or Hortisol, alternating with a fertiliser high in potassium (3:1:5). Your bonsai can be fed every 3 weeks.
Keep a close eye on the training wires for your bonsai, as gross feeders such as Figs and Brush Cherries bulk up quickly and the wire could cut into the branches. You can still re-pot Figs, just keep them out of the sun for at least 3 weeks.
Weed your garden beds and your bonsai regularly. Remember to replenish the mulch in your garden beds this season as this will assist in decreasing the growth of weeds and will also keep the soil moist during this time, lowering your watering requirements further. The mulch will also provide a neat finish to your planted areas.
If you are at home these summer holidays and wish to give your garden a quick splash of colour, focus on the entrance to your home, the edge of paths and your patio. Early summer is the ideal time to plant containers, such as patio pots, window boxes and hanging baskets, so take a quick trip to your local garden centre and select trays of seedlings or bagged plants already flowering to provide you with stunning colour within a short space of time.
At your entrance, welcome your visitors with pots of brightly coloured flowers. If the entrance is sunny, choose from (indigenous and non-indigenous plants) marigold, salvia, nicotiana, petunia and vinca, with trailing lobelia and alyssum to soften the edges of pots. The Madeira series of Marguerite daisies (argyranthemums) are compact in growth and full of flowers, making them ideal for containers.
Plants suitable for shady entrances include hydrangeas in half barrels or large pots and in smaller pots: fuchsias, bedding begonia, impatiens and the wishbone flower (Torenia). Torenias are compact (30cm) bushes with dainty flowers of blue, purple or pink with yellow throats, suitable for borders, beds, hanging baskets and window boxes.
For your patio, have large containers overflowing with plants that are more eye-catching and require less watering than small pots. Add water-retentive granules to the potting soil to retain moisture.
Pots of scented dwarf gardenia, liliums and nicotiana will add to the pleasure of being outdoors. Both ivy leaf and zonale pelargoniums are suitable for pots and hanging baskets, and a delight to any touch are the scented pelargoniums with leaves smelling of rose, citrus, nutmeg or peppermint when crushed.
Because they are continuously on show, plants on patios need to be deadheaded, old foliage removed and fertilised regularly. Water daily during dry weather. Dead heading is generally listed as a spring chore, but you should continue to dead-head flowers throughout the summer as this increases flowering time and strengthens the plant.
The most popular of the Hydrangeas (commonly known as Christmas flowers in South Africa) are the big leafed French Hydrangeas and this month they are the pride of the garden as they come into full bloom. There are many varieties to choose from including the new "Endless Summer" variety that is the world's first repeat flowering hydrangea flowering throughout the late summer.
Caring for Hydrangeas is easy: they prefer morning sun or dappled shade all day as long as they get protection from the heat of the day, in a moist but well drained soil. As the colour of the flowers are influenced by the pH of the soil - blue if acid and pink if alkaline - use eggshells in the soil or add acidic compost for more blue flowers or for more pink flowers add agricultural lime.
All Hydrangeas appreciate a little extra effort when they are first brought home. Although most will tolerate some neglect, they do best in a well-prepared garden bed. Dig the hole at least 2 times the size of the original pot. Mix 1 part compost or acid compost to the excavated soil with a handful of organic pellets, insert the plant, mound the soil slightly and soak well.
Although hardy and relatively disease free there are a few things that can hamper the performance of your Hydrangeas. The most frequent issue is yellowing leaves. There are two types of yellowing leaves: general yellowing on old leaves is indicative of an iron deficiency, while yellowing on new leaves where the green veins are visible on the yellowing leaves is indicative of iron chlorosis.
Iron chlorosis can be corrected by the addition to iron to the soil. and can be applied annually or whenever symptoms reappear.