Citrus one of many plants for May

By GEOFF MIERS

The Covid-19 movement restrictions had an upside: Many people turned to gardening.

May is a fantastic month for it as daytime temperatures are ideal with soil temperatures still warm promoting strong root growth. We have had a fantastic mild summer with good rains and autumn is being very kind so far.

Whether planting fruit and citrus trees, establishing a winter vegetable garden, adding winter and spring flowering annuals, creating a herb garden or establishing a native garden, the options are literally endless. 

Native perennials will thrive if planted this month. Don’t forget to pay a little attention to the soil prior to planting and at the very least introduce a planting fertiliser tablet into the hole prior to planting.

A little potting mix blended into the soil will improve the soil’s water holding capacity and stimulate microbic activity, these microbes breaking down organic matter releasing valuable nutrients that assist plant growth.

If the soil is a little heavy or salty adding gypsum will improve the soil’s structure and of course do not forget to add some plant nutrients.

You must never plant into dry soil, only into moist soil.

Planting into dry soil will quickly kill off the very fine hair roots of a plant and immediately shock the plant resulting in a dramatic set back to the plant settling in and immediately putting on a growth spurt. This is often the cause of healthy plants dying back or even dying off completely.

May is a fantastic time to work away in the vegetable, herb and flowering annuals gardens. The array of plants that can be introduced now are vast and varied.

Early to mid May is an ideal time to be planting citrus. Citrus are a great investment in the future, provide an element of the exotic to the garden and can be productive in two to three years providing everyone with fresh fruits that can be harvested daily for months.

New season’s citrus stock have arrived at most nurseries, this being a signal that it’s time to plant citrus.

Continue to plant out the veggie garden with a wide variety of root crops and leafy greens. Leafy plants will appreciate a side-dressing of nitrogen to promote strong leaf growth. Regularly liquid feed all vegetables.

This month is an ideal time to plant broadbeans, peas, cabbage, broccoli, onions, Swedes, radish, carrots, shallots, silver beet, spinach, Asian greens and lettuce.

Celery, chives, spring onions, coriander, parsley, snow peas, cabbage, kale and leeks also thrive if planted now. 

Continue to plant strawberries as planted now they will be established by next spring and will flower and fruit prolifically as the warmer months arrive.

Winter flowering annuals should be planted now. Ageratum, alyssum, snap dragon, calendula, carnations, chrysanthemum, delphinium, dianthus, lobelia, marigolds, pansies, poppies, primula, stock, sweet peas, viola and wall flowers can all be planted now.

Some time may be required pruning select plants in the garden. Prune Autumn flowering perennials once flowering has finished and continue to dead-head roses to prolong their flowering season. Prune Chinese mulberry trees at leaf drop, sometime between late May to mid June.

It is a good time to tidy up citrus in need of a little attention, concentrating on shaping and removing dead wood and removing heavily pest infested timber or diseased wood.

Pruning now to stimulate new growth is however not recommended as new growth will be emerging in around the second week of June – not far away from potentially heavy frosts that will kill off new foliage growth.

Leave pruning to stimulate new growth until late June or early July with new growth wanting to emerge with the first flush of growth as spring arrives.

Because of the long hot summer many people neglected to feed their citrus trees in late January to early February. Because of this I have been recommending giving citrus a quarter of their nutrient needs now and them giving them two-thirds of their annual nutrient needs in early August. 

Do not forget to reduce watering generally throughout the garden as the evaporation rates drop quickly.

This is equally important for indoor plants. New plants introduced into the ground will still require watering daily until they send out a new root system at such time the watering can be reduced back to watering once every two to three days depending of your soil conditions and the plant variety.

Cut back dramatically the water given to deciduous fruit trees and grape vines once they drop their leaves. A good drink once every month will meet the these plants’ needs which are quite minimal over the coldest months of the year.

On the pest front watch for tree boring grubs as they become active on many acacias and eucalyptus this month. White cabbage butterfly becomes a problem now as are aphides and a variety of leaf eating grubs and caterpillars. Mealy bug numbers will have also built up and need to be managed.

In the vegetable garden watch for small holes appearing in some Asian greens and rocket particularly as these holes will be caused by a tiny little beetle called the flea beetle.

They are hard to see however quietly sneak up on the garden and give the plants a brush and you should seen them jump for cover.

Flea beetles can be managed by spraying with the environmentally friendly Pyrethrum that has a with-holding period of 24 hours, meaning you can spray one day and harvest, wash and eat the next day.

Watch for eggs being laid on new growth on citrus as the citrus butterfly is active at the moment. These tiny creamy or yellow eggs can be removed manually and squashed.

Alternatively spray your citrus every 12 to 14 days with Dipel. This will keep the grubs under control.

Dipel is an environmentally friendly management method. In using Dipel you are simply covering the plant with a dormant bacteria that is activated once consumed by a grub or caterpillar.

The bacteria is safe for humans, dogs, cats, birds and all reptiles, it is only lethal for all grubs and caterpillars.   

Many eremophilas, hibiscus, citrus and a variety of other plants have infestations of mealy bug, cottony white scale and a variety of other scale types that have built up over the hot months of the year.

These are best treated now with temperatures having dropped. White oil, eco oil, and Natrasoap can all be used confidently with little likelihood of leaf burn once temperatures have dropped below 30 degrees.

Mealy bug can be difficult to eradicate. Prune off worst affected parts of the plant, hosing down with a sharp jet of water will remover 95% of the problem and there are systemic pesticides that can applied to the ground that will be taken up by the tree and will kill off any mealy bug feasting on the tree.