Planting spring bulbs

The autumn equinox (when day and night are of equal length) occurred on Tuesday, March 20th, this year. Days are becoming shorter than nights now, and it is time to prepare soil for planting spring-flowering bulbs. These plants thrive in a compost-rich soil with some complete organic complete fertiliser added. Gardeners in Cool climates and New Zealand can plant bulbs now. However, as these bulbs grow better after a period of chilling, gardeners in warmer areas can put bulbs into the vegetable crisper of the fridge for about a month before planting.
Bulbs are normally planted at a depth twice the width of the bulb. In Warm climates, plant suitable bulbs up to twice as deep as indicated on the packet. After planting, mulch the area in early morning when the soil is cooler and keep the planted area just damp until growth appears. For moon planters, Full Moon phase is the best time to plant bulbs.

Frangipani trees from seed

I often receive e-mails with questions about growing frangipani trees, and some readers may like to try growing them from seed. Paula Pugh Schipp of the Frangipani Society of Australia says that frangipani trees grown from seed grow much faster than those grown from cuttings because the root system starts to form when the seed germinates. Another advantage of propagating these lovely (Plumeria) trees from seed is that trees grown from cuttings will always be the same as the parent tree, but trees grown from seed are, like children, not usually exact duplicates of their parents. You may grow a tree with flowers with an entirely different colour combination if you have a variety of frangipani trees in your area.

Frangipani flowers do not always produce seed as the self-pollinating flowers do not always release their pollen. You can try hand-pollinating flowers with a piece of thick fishing line. Place the end of the line deep into the flower and wriggle it very gently to release the pollen. You have to be gentle as it is easy to knock the flower from its stem.

Seeds develop within a pod, often a double pod in a ‘T ‘ shape, which looks rather like two thin 17 cm zucchini in the early stages – changing over time to brown/black when mature (see photo, lower left). Pods can take up to 8 months to mature depending on the local microclimate.

When the seeds are mature, the pods become brittle and begin to split open revealing up to 60 seeds in each pod. Collecting the seed takes a bit of good timing because each of the seeds has a small ‘wing’ attached and, when the pod completely opens, the seeds can be spread far and wide on the breeze (see photo, below right). If the pod is in a position where you can easily observe its development, when the pod is just beginning to split, place a large basin under the pod structure and carefully cut the adjoining stem from the tree. If the pod is high in the tree and hidden by foliage, then when the pod starts to change colour, make a bag from nylon netting large enough to hold the pod structure with some room to spare. The will prevent the seeds from blowing away when the pod opens.

If you would like to try growing frangipani from seed, for best results sow them soon after they are collected.

This excellent Frangipani website provides a detailed guide to propagating frangipani, including an interesting method of germinating seed in paper towels: Frangipani Society of Australia

Powdery mildew on zucchini

A reader has asked about powdery mildew on zucchini plants and fungus-eating ladybirds:
Hi. Wonder if you can sort this.
1. Most fungi need moisture and organic material. This seems to be supported by my zucchinis which seem to get worse powdery mildew when I get water on the leaves. I have read that they like dry weather. Is there evidence for either opinion?
2. Some people say that the ladybirds that feed on this mildew spread it by carrying spores, others reckon they are a controller, eating the fungus down. What is the evidence please for either of these?  Many thanks, Barb

Powdery mildew is likely to occur on stressed plants in humid weather when temperatures are between 11-28° C. and, once established will continue to affect the plants even if weather becomes dry. Avoid wetting leaves whenever possible Barb. However, because they like low-humidity weather, it doesn’t mean that they are drought tolerant. Zucchini and some other members of the cucurbit family (melons and squash) produce a lot of foliage and need plenty of water and fertiliser. An efficient way to water this group of plants without wetting the leaves is to put a large drink container (with the base and cap removed) neck downwards near the roots so that all the water goes directly to the root area where it is needed, (see photo). Keep topping up the container until it empties slowly.
The yellowish ladybirds with 26 or 28 spots are the only pests of the ladybird family. They eat the leaves of stressed plants of cucurbits. The beneficial fungus-eating ladybird and larvae can be clearly distinguished from the pest in the photos below. From the far left is the ‘Fungus-eating ladybird’, then the leaf-eating ’26 spot Ladybird’ that damages plants. Next is the larva of the ‘Fungus-eating Ladybird’, which also eats fungus and, last of all is the prickly larva of the ’26 spot Ladybird.

Rather than blame the fungus-eating ladybird for spreading the disease, gardeners should check that their plants have sufficient water and nutrients to avoid stress, and the soil pH is suitable for them to absorb what they need for healthy, disease-resistant growth. Also see Powdery Mildew for treatment of this disease.

Manure and mulch warning update

Last October I updated the warning about pyridine herbicides that can damage or kill both food crops and decorative plants. Unfortunately, some readers have since had plant damage after inadvertently purchasing manures or mulch that contain one of these herbicides, despite a NSW government website stating that no damage has occurred in Australia.
As a result, I am posting a reminder.
Pyridine herbicides are only effective on broad-leaf plants, but the chemicals remain active in mulch cut from sprayed pastures and in manure from animals that have grazed on sprayed pastures until the chemicals are broken down by soil microbes. Of particular concern to home gardeners and councils that recycle waste into compost for agricultural and domestic use are the products containing aminopyralid, clopyralid and picloram because they are quite persistent, and residue from these herbicides can damage plants for up to 24 months. However, because the Australian Pesticides and Veterinary Medicines Authority (APVMA) regards the person who sprays the herbicide as the ‘end user of the product’, any warnings are limited to product labels without any regard for unsuspecting gardeners who, in good faith, purchase mulch, compost or manures contaminated with the herbicide, and who may not recognise the cause of the damage to their crops because they have not personally used any herbicides.
A recent check of their website shows that the APVMA has registered 233 herbicides that contain at least one of the pyridine group of herbicides – an impossible list to check through before purchasing mulches, manures or compost. The entire tomato family, lettuces, sunflowers, spinach, strawberries and legumes are particularly susceptible to damage from these herbicides, which can also affect a range of ornamental plants.
To protect your garden from pyridine herbicide damage: only use aerobically composted manures on gardens. Aerobic composting requires weekly turning or stirring to ensure the composting process is carried out by microbes that require oxygen. Breakdown of the herbicide will be very slow in compost heaps that are not aerated.
Mulch that carries an organic-registered label does NOT contain any herbicides. Mulches from uncertified sources are high-risk products because the drying and baling of mulch materials eliminates microbial action, and the herbicide will still be active. The only safe compost to purchase is organic-registered compost.

If you are unable to purchase certified-organic manures or mulch, test the safety of the product by sowing some seasonally suitable peas or beans in pots containing certified-organic potting mix (with the manure mixed through it) or covered with the purchased mulch. (Water this pot through the mulch). Keep the test pots well-watered to eliminate other sources of stress. You should be able to see if an input is contaminated within 21-28 days. Dispose of any affected plants and potting mix with household garbage.
Symptoms to look for are:
Poor germination or death of seedlings, twisted, cupped or elongated leaves and twisted growth, misshapen pods.

Return remaining contaminated inputs to your supplier. If this is not an option, aerobic composting is the quickest way to break down these herbicides. Test the mature compost for herbicide residue.
If you find that the mulch has been affected, use it on beds that you can leave fallow until aerobic microbes in topsoil break down the herbicide or, if space is limited, compost it aerobically. if you find that garden beds have been affected, dig organic-registered compost through the bed and keep it damp to keep soil microorganisms breaking down the herbicide as quickly as possible.
Notify your supplier of the problem as pyridine herbicide product labels state that treated crops are not to be used for hay, silage or animal bedding, and manures are not to be spread on land used for growing susceptible crops.

Please also take a minute or two to notify the APVMA of problems with these herbicides. The APVMA encourage the public to report pesticide problems through their new Adverse Experience Reporting Program (AERP) by e-mail:, phone 1800 700 583, or fax: 612 6210 4813.

Further information:
Examples of pyridine herbicide damage

You can find Australian product names of these herbicides by going to the APVMA’s Public information (PUBCRIS) page. Under product type select ‘herbicide’, then type aminopyralid, clopyralid or picloram in the active constituent panel. Click ‘Search’.

The NSW Government has been aware of the problems with these herbicides in Australia since 2005: see  Organic

Frogs like bromeliads, too.

Bromeliads are an interesting group of plants with over 800 varieties. Some bromeliads are epiphytic (grow on trees or other objects for support) while some require soil for their roots – including the most well-known member of the family – the pineapple plant (Ananas comosus). Bromeliads are very easy to grow in warm and temperate climates, and have an amazing range of foliage and flower shapes and colours. Most bromeliads grow in a rosette form with a central well, and their unusual flowers grow from the central well.

The blade leaves of bromeliads funnel a lot of water into the central well, providing moisture for insects and other small creatures in times of drought, and the insects provide organic matter to fertilise the plants. This regular supply of food and water also attracts frogs.

If you like having frogs in your garden, try growing some bromeliad genera with soft, leathery, broad leaves – for example Aechmea, Neoregalia, Vriesea or Bilbergia, which grow best in part shade around the base of trees. These bromeliads rely mostly on their central well for water and food, and use soil mainly for support. The rosette of leaves also provides a hiding place for frogs.
Plant in autumn in warmer areas or spring where winters are cold. Grey-leaved bromeliads absorb moisture from the atmosphere and do not need soil, and bromeliads with heavily barbed leaves do best in acidic soil in full sun.

Open-pollinated seed suppliers

Organic gardeners use untreated open-pollinated seed. Open-pollinated seed varieties are selected for consistent vigour, nutrient levels and flavour. You can save mature seeds from these varieties because they reproduce true to type. The benefit of saving seed from your own crops is that the seed will have come from plants that have adapted to your local growing conditions.

Sometimes you will see ‘F1′ after the name of a seed variety. This is hybrid seed where two parent plants have been self-pollinated under controlled conditions for up to 10 generations before the parents are cross-pollinated to produce their first filial (offspring) seed – known as F1 seed. So-called hybrid vigour only exists for one generation, as seed collected from plants grown from hybrid seed is either sterile or reverts to the characteristics of one parent. Consequently, it is not worthwhile trying to save seed from hybrid plants.

You can find more about different types of seed, including GM seed, in my book Easy organic Gardening and Moon Planting, pp 138–140.

Open-pollinated vegetable, herb, flowering annual and green manure seeds are available from a range of suppliers, including those listed below. Seed packets are approximately $3.00-$3.80 each. Seeds from some suppliers can be purchased at retail outlets and some have on-line catalogues for easy browsing. The eastern mainland states of Australia can order seed by mail from other states if there are no local suppliers, but Tasmania and Western Australia have restrictions on some species of seed. Suppliers for Tasmania and Western Australia are listed separately.

Greenpatch Organic Seeds (NSW) –
A wide range including bulk seed and a green manure mix. Seed is also available from some retail nurseries.
Ph: (02) 6551 4240 email:

Green Harvest Organic Gardening Supplies (Qld) –
A wide range including green manure mixes (inoculants included), and organic gardening products.
Ph: (07) 5435 2699 email:

Eden Seeds (Qld) –
A wide range including bulk seed and green manure mixes (inoculants included if available). Seed is also available from some retail nurseries.
Eden Seeds also have a certified organic range of seed (some imported) at –
Eden Seeds and Select Organic Ph/Fax: (07) 5533 1108

Heirloom Harvest (SA)
A good range of traditional, heirloom, open-pollinated vegetable and herb seeds.

Fair Dinkum Seeds (QLD)
An interesting range of open-pollinated vegetable, herb and ornamental seeds, including some unusual varieties.
Email form on website.

Mr Fothergills Seeds (NSW) –
A limited range of certified organic seed, but mostly hybrid seed.
Available from some retail nurseries.
Ph: (02) 45775457 e-mail:

Diggers Seeds (Vic) –
A limited range of certified organic seed, but mostly open-pollinated seed and some hybrid seed. Seeds are cheaper for members of Diggers Club.
Ph: 03 5987 1877 email:

The Seed Savers Network
This network saves and shares open-pollinated seeds. Phone/fax: 02 66856624

Cornucopia Seeds (Vic)
Open-pollinated and heirloom seed, and organic gardening supplies.
Ph: (03) 5457 1230 Send email from web site.


Phoenix Seeds
Open-pollinated vegetable, herb and flower seed, and some hybrid seed.
Voice mail: (03) 6267 9663 email:

Four Seasons
Organically grown open-pollinated vegetable and herb seed.
Ph: 0412 721 268 email:

Western Australia

Bay Seed Garden
Organic seed producers of non-hybrid and heritage vegetable, herb and flower seed. List available – send 1x55c stamp.
Ph: (08) 9752 2513 Mail: PO Box 1164 Busselton WA 6280

Organic vegetable and herb seed. Seed is also available from some retail outlets.
Ph: 0400 239 258 email:

Eden Seeds (Qld) –
Has green manure mixes (inoculants included if available) that can be shipped to WA.
Eden Seeds Ph/Fax: (07) 5533 1108

Soil pH is so important

I’ve had several e-mails recently from gardeners who have used purchased soil or organic fertilisers and found that their plants were sickly or not growing because they were growing in soil that is too alkaline.
Soil pH (acidity or alkalinity of soil) is extremely important because determines which nutrients are available to plants. All the major nutrients are only freely available to plants within a narrow soil pH range of 6.5 to 7.5, where essential trace elements are also available, and aluminium is locked out.
See What’s soil pH?

Lime should only be added to soil where testing of soil pH shows a need for it. Mushroom compost and poultry manure (including dynamic lifter) can be quite alkaline, and some suppliers are now adding lime to bagged cow manure and horse manure because some customers objected to the smell, (usually caused by nurseries leaving bags sitting in hot sun). And, only agricultural lime (calcium carbonate) should be used when liming is necessary as hydrated lime can burn plant roots and reduces nitrogen levels through conversion to ammonia.
When purchasing soil, always check the pH before adding fertilisers or lime to it, and always test the pH of your compost before adding it to the garden (well-made compost has a pH of around 6.0-6.5). If soil pH is not higher than 8, you can reduce the pH using elemental sulphur (according to the instructions on the pH kit) and dig into topsoil a 5cm layer of well-made compost, which will buffer plant roots from the unsuitable pH. Or, grow a legume as a green manure while waiting for the pH to reduce. Slash the legumes as they start to flower and dig them into the top 10 cm of soil. See Soil pH too high? , also Changing soil pH.

If the pH is higher than 8, it is not easy to reduce it with sulphur alone. As organic matter breaks down in soil it releases hydrogen ions that will replace the calcium ions in the soil, and gradually reduce the pH. Cow, horse or sheep manure (but not poultry manure) under mulch will also reduce the soil pH gradually as it breaks down. However, be very cautious where you source manures and mulch as more farmers are using herbicides that remain active in manures and mulch materials (except lucerne and pea straw) until they are broken down by soil bacteria. Test soil every 6 weeks after digging in the green manure, and you can use it for general vege growing when it gets below 7.5.

Greenpatch Organic Seeds Open Day

If you are in the Taree area this Sunday (23rd October, 2011), Greenpatch Organic Seeds are having an open day from 10:00 am to 3:00 pm. Activities include a tour of the farm, garden and nursery; demonstrations on saving particular types of seed, and a seed-saving workshop for home gardeners so that you can learn how to save viable seed from your own backyard crops.
Members will receive a 10% discount on purchases.

For directions to Greenpatch, email: – or phone 02 6551 4240

Camellia leaf gall

If new leaves on Camellia plants become thick and very pale green or pink, and the underside of the leaf starts becoming white – the plant is suffering from ‘Camellia leaf gall’. This is a fungal disease that affects tender new growth of Camellia sasanqua (and sometimes Camellia reticulata), especially in very humid or wet, shady conditions. Fungal diseases are a sign that growing conditions are stressing your plants and their immune system is compromised. There is no organic or chemical treatment for this disease. However, an application of seaweed extract tea will help to strengthen the cell walls of the affected plants and make them more resistant to disease.

But, first the affected growth must be removed, preferably before the undersides of leaves develop white spores. You will need a baked bean tin containing about 5 cm of methylated spirits to sterilize secateurs blades, and a large garbage bag for the prunings. Prune off all affected growth (swish the open secateurs in the spirits often while pruning) and place it directly into the garbage bag. Also collect in the bag any fallen leaves as they can harbour the fungal spores that will activate this disease again when conditions are suitable. Seal the bag and put it in the garbage if you are unable to burn the leaves. Do not compost them. Then give the soil around the plants a drink of seaweed extract at the recommended strength, and protect the soil surface with 3–5 cm of fresh mulch. Make sure your camellias are watered when the top centimetre of soil is dry, but afford watering the foliage. Also give the plants an annual application of compost or complete organic fertiliser and seaweed extract tea in late winter.

See below, how affected new growth appears, and close-up of affected leaves.

Photos courtesy of A. Lavick.

Frangipani stem rot

A New Zealand gardener is having trouble with her potted frangipani. I am posting my reply separately as other gardeners may have had a similar problem:

I live in Auckland NZ. I have white frangipani over 1.5m tall in a large pot. It last flowered about 4 years ago which was it’s first year in the pot. Now we are getting good leaf growth and new stems in the summer but the new stems rot in the winter and we have to cut them off.

There are several reasons why new growth on frangipanis can rot in winter – (1) water-logging of the mixture while the tree is dormant. (2) Lack of nutrients, such as potassium, which strengthens cell walls as well as promoting flowering. Have you given the tree any fertiliser? (3) Its position in winter is too cold for a tropical tree.

Remedies for (1) and (2): If your tree has been in the pot for 4 years, it is quite possible the roots have blocked the drainage hole/s, and that is causing the softer, new growth to rot when the tree is not using the moisture in the pot. Or, perhaps the holes have become blocked if the pot is in direct contact with the ground. Frangipanis form lots of roots and they must have good drainage.

As their roots are rather brittle, if you can’t remove the root ball from the pot easily, lie the pot on its side and hose out the potting mixture. Then carefully re-pot it into a larger pot with fresh potting mix that contains some complete fertiliser, and gently water it to settle the mix around the roots. If you can’t find a larger pot for the tree, trim the longest roots (so that they will have to grow about 5 cm to fill the pot) and re-pot in fresh mix in the same pot. Sit the pot on some pieces of tile so that the drainage holes remain clear of the soil.

Remedy for (3): Even the white frangipani (which is the hardiest) will not do well if temperatures are too low or they are in windy positions. When growing frangipanis in temperate zones, on the north side of a wall is a good position for them. A brick or concrete wall is best because the wall absorbs heat during the day and releases it slowly at night, keeping the air around the tree slightly warmer.