The Western Australian Rare Fruit Club
Garden Newsletters

May in the suburban orchard


Whether you have a suburban back yard or live on acreage or a larger block, it's very important to have your soil so that it supports and sustains plants by providing a source of nutrients and water for your fruit trees.

One of the essential components of a fertile soil is humus and compost. 'Humus' is taken to refer to the actual organic content of soil. Humus has an influence on the retention and release of nutrients, the formation of good soil structure and the soils ability to hold water.

A soil must have good structure if plants are to thrive. Remember all terrestrial life depends on your soil. Everyone probably thinks they know a bit about soils, as after all, you have spent your life walking on it and playing in it.

At the site visit on May 1 in Leschenault, the owners have done a huge amount of work in producing a soil that is turning their gardens into a magnificent site. It is fun to work in soils, undertaking soil amendments to our poor Bassendean sands to produce rich soils growing fruit, flowers and vegetables.

We all must improve the health of our soils. Please check your soil pH levels at least twice during the year. An acid soil of 4.5 will be deficient in the following nutrients: nitrogen, potassium, sulphur, calcium, magnesium, molybdenum and copper. It can also mean you can have toxic levels of manganese and aluminium in acidic soils.

An alkaline soil of 8.5 will be deficient in phosphorous, iron, manganese, boron, copper and zinc. On acid soils, I like dolomite to increase my pH; dolomite contains calcium and magnesium or lime, which is calcium. On alkaline soils use iron sulphate to reduce the pH of heavy clay, and to make the heavy clay more friable, use gypsum. Remember when plants and trees are deficient in nutrients, they have a way of showing their deficiency through their leaves.

Remember soil pH determines the plants’ ability to draw up nutrients from the soil. Strong and healthy plants which get sufficient water, nutrition and sunlight, will build up a natural resistance against pests and diseases.

April was a great month for plants and trees to grow with some of the citrus varieties now producing juicy sweet fruit, especially the mandarins. I recently tasted an Imperial Mandarin down at Wokalup which had an exceptional flavour, and this tree was loaded with fruit. Imperials do have a habit of alternate year fruiting, producing a large crop then a medium size crop of fruit.

Early seasonal rains also ended many months of dry and hot normal summer weather, so now hopefully May will be cooler and more acceptable to plants and humans. With early rains in our suburban orchards, there are many weeds appearing in our yards, so it is important to start getting rid of these plants before they are too hard to eliminate. Pull them out by hand, spray them or use some organic measures by applying hot water and/or using vinegar. Just recently a local Community Garden purchased a fire wand which sends out a flame, burning many weeds. It is propelled by a small gas cylinder and is about $90.00.

What to do in the orchard during May.

The month of May is very important to home orchardists, time to look at your stone fruit, especially nectarines and peaches. As the leaves start to fall off these fruit trees it will soon be time to spray for the leaf curl fungus that attacks your trees.

Copper-based sprays must be used on all stone fruit, and this disease of the foliage causes distorted and crinkled leaves and sometimes will kill the first leaves after they emerge even though the trees will produce new foliage. The crop can suffer and the tree can become weakened and die. The timing of sprays for this disease is very important. Once the buds have opened it is too late, as the fungus has already entered the leaves.

Always spray a Bordeaux mixture or any copper spray at bud swell. If you have had problems with leaf curl in the past it is recommended to apply 2-3 sprays before the buds turn into flowers, and do this over a few weeks. I already have flowers on my nectarines and quinces, so it is far too late to spray, so I am hoping that I don't have leaf curl. After all it is a brand new orchard with no stone fruit for a couple of kms.

If you have lawn in your garden, cut your grass back to about 5mm high in May, turning the grass into compost, mixing with straw and other garden materials, add dolomite and molasses as an activator.

It is ok to prune stone fruit now as some people like to do this job at dormancy. I like to prune in January after the tree has finished fruiting. Winter pruning can lead to diseases in your tree. It is your call as to when you cut back and prune. Mulberries should be cut back after leaf fall, in about June. Do not prune your grapes until about the 1st August or when the sugars or carbohydrates have stopped running.

Keep your secateurs sharp and always drop these into bleach after you have used them to keep diseases out of your orchard. Disinfect your wheelbarrow, shovels, pots, rakes, hoe and any other garden equipment you are using.

Seedlings can still be grown in a heated propagator that keeps seeds warm and moist and encourages them to germinate.

Pineapples take about 18 months to grow and fruit on the Swan Coastal plain. This is my new bragging rights in fruit production. My plant was grown in a pot and was under semi-shade with mobs of water.

It is important to attract the good bugs into your garden, so don't spray everything that moves otherwise your garden problems will increase.

Fruit Fly.

We all can have fruit fly so it is important to work hard at getting rid of this nuisance.Hang baits in trees when fruit starts forming and replace them every two weeks.

Pests and Diseases in your Orchard

If you have a small nursery in your back yard, or you live on a hobby farm or acreage it is very important that you prevent pests and diseases entering into your nursery. It is really important to have great nursery hygiene, making sure the nursery stays weed free and also pest free.

Diseases can be spread in your small backyard nursery in a few ways including soil, in untreated commercial media, in water, on seeds, cuttings and vegetative material. Diseases can also be brought in on tools, equipment, containers, from vehicles, dirty hands and air. Make sure you clean all your benches with methylated spirits, clean your pots and tools with bleach or chlorine and use and make a foot bath when entering your nursery.

Ways of preventing the spread of pests and diseases in your backyard nursery include the following:

  1. Weeding and removal of diseased materials from the area.
  2. Removal of all rubbish.
  3. Cleaning up and sterilising equipment.
  4. Safe use of equipment.
  5. Washing surfaces and hands.
  6. Pot washing and sterilising pots and equipment.
  7. Using accredited media supplies and therefore sterilised potting media.
  8. Your nursery also needs adequate drainage of water runoff.
  9. Treatment of water used in misting sprays.
  10. If you collect native tree species and want to propagate by seed it is very important to use smoke water in your soil or even soak your seeds in smoke water.

Soil-borne pathogens or fungi can cause dampening off in the nursery and they can rot your seeds and seedlings before they germinate or the stems when they emerge.
Rhizoctonia can attack the seedling stems.
Phytophthora or dieback can be transported into your nursery in soil and water. It will not only kill seedlings but fully grown trees, as it affects the root system and prevents the roots from functioning and supplying the plant with water and nutrients. I do believe avocado trees can now be purchased on Ecuadorean rootstock that is resistant to dieback.

Air-borne pathogens such as Botrytis or grey mould is another pathogen that can spread and affect stems and leaves. For good management avoid overcrowding in your nursery set up.

Bacteria. Some bacteria is beneficial to plant growth but some bacteria can affect certain plants.

Pests. Rodents and other seed-eating insects can be a problem in storage boxes. Plants can be eaten by kangaroos, rats and possums.

Nematodes. Occur mostly in unpasteurised soil.

Sap sucking insects. Insects such as white fly, mealy bugs, thrips, aphids and two spotted mites.

Crickets, slugs and snails. They will eat seedlings and soft vegetation.

Bird and bee attracting plants for your garden

Small to about 1metre
Anigozanthos species or Kangaroo paws.
Grevillea lanigera or Mt Tamboritha
Callistemon Little John

Medium trees and shrubs
Kunzea baxteri
Calothamnus quadrifidus Blue wrens, bees and honey eaters love this prickly shrub.
Callistemon Endeavour, which is a type of Bottlebrush.

Larger trees
Eucalyptus caesia or Silver Princess
Eucalyptus leucoxylon Rosea (one of my favourite hybrids)
Acmena smithii or native local Lilly Pilly.

All these trees can be grown on the Swan Coastal plain and will grow on our poor soils. If trees flower and do not bear fruit, poor pollination is likely to be the cause. Sometimes unpollinated flowers produce fruitlets, which will develop for a while and then drop off. This is quite common in cherries and plums. This major problem can be caused by the absence of a suitable pollinator in your area such as bees or other pollinating insects.

So I have included the above articles on bee and bird attracting trees for readers to plant near their orchard.

Question Time.

I normally receive a few questions during the week on gardening and some of the better ones I have included in this month's read, however I have not included some queries from readers especially the great backyard orchard question about the Home Grown lemon tree.

I have a lemon tree but I think it has died, so what can I do with it?
My lemon tree will simply not grow, and I have fed it many times and will still not grow. Why?

My answers to these questions should not be printed in a family newsletter.

A great lemon question is, when should I plant a lemon tree? My call is all-year-round as they are readily available at most nurseries during the year.

How do I know when to re-pot or pot on my fruit tree?

If you are growing your fruit trees in a pot, repot when the root ball feels firm or the pot is starting to split and the roots are emerging from drainage holes, then choose a pot that is 50% larger than the previous pot.

With our new committee we are encouraging members to send in articles about Fruit trees in the orchard, to be presented in a regular segment called 'Members Write…'. If you would like to help out in content for our magazine please send in information, for example - about what's happening in your garden, fruit you have tasted somewhere, something you saw or learned.

Members Write…

Here's a rare one for WA - Pouteria fossicola which is very closely related to Mamey and green sapote. It hails from Central America and in this preferred tropical environment can grow up to 30m high, a similar size to the other two. All three are much smaller in cultivation and would likely be further dwarfed here in WA with our non-fertile soils, hot and dry summers and non-uniform seasonal precipitation. The fossicola fruit is the largest of the three and is reported to be delicious with an almond-like aroma. Plants are self-fertile, which is an advantage over the better known Mamey that is more commonly dioecious. I acquired two seeds recently and one of these has now germinated. Will be a challenge to get it through its first winter and onwards but here's hoping. --Troy Bailey.

Pouteria fossicola Pouteria fruit on the tree. Spacer

Ancient genetic modification…

The practice of grafting plants has been widely used for more than a thousand years. A short article by Michael Le Page in New Scientist magazine, 12 March 2016, tells of a series of studies of grafting. The first study in 2009 showed that cells on either side of a graft could exchange chloroplasts — the organelles that carry out photosynthesis and have their own small genome.

In 2014, another study found that the entire nucleus of a cell could transfer across a graft and be added to an existing cell nucleus, fusing the two genomes.

Now a new study has shown that cells on either side of a graft also swap mitochondria — energy-generating structures with a small genome. Once entire mitochondria from one plant get into another, their DNA is mixed together.

Genome swapping only takes place close to the site of the graft, but a bud in that region can grow and can give rise to new plants with mixed genomes. Because grafting has been done over such a long time span, it is likely that some of the plants and fruits we eat were created by this accidental GM. So far, no one has looked for evidence of this, but now they know what to look for, new avenues for creating new plants will open up. --Pat Scott

Rollinia fruit ripeningDoing a bit of spraying this afternoon and noticed the first rollinia fruit to be ripening.--Barry Madsen

In September the WA Rare Fruit Club has pencilled in a Citrus Grafting Workshop, this will be done by our grafting gurus Michael.

Time, venue and date have not been decided on so just pencil in September for this important event in your diary.

Remember to always wear your PPE in your garden and orchard, so gloves, hat, boots, long sleeve shirt and safety glasses are all important.

With many seasonal fruits in season, particularly olives, citrus, guavas, passionfruit and quinces, maybe some readers could supply a recipe from one of these varieties to share with us at the RFCWA.

What I would be interested in is for someone to come up with a simple design for the cover page of the Newsletter. Are there any green artists in our group?

Don't forget Saturday 14th May for our next property visit to Donna and Jim's garden in Nedlands.

Next Month
The flowering pattern of avocados.
The Sapote family
Plus other news that hasn't happened yet.

Catcha and Happy gardening.


John Bodycoat