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: aerp@apvma.gov.au, 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) – www.greenpatchseeds.com.au
A wide range including bulk seed and a green manure mix. Seed is also available from some retail nurseries.
Ph: (02) 6551 4240 email: enquiries@greenpatchseeds.com.au

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

Eden Seeds (Qld) – www.edenseeds.com.au
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 – www.selectorganic.com.au
Eden Seeds and Select Organic Ph/Fax: (07) 5533 1108

Heirloom Harvest (SA) www.heirloomharvest.com.au
A good range of traditional, heirloom, open-pollinated vegetable and herb seeds.
E-mail: info@heirloomharvest.com.au

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

Mr Fothergills Seeds (NSW) – http://mrfothergills-seeds-bulbs.com.au
A limited range of certified organic seed, but mostly hybrid seed.
Available from some retail nurseries.
Ph: (02) 45775457 e-mail: sales@fothergills.com.au.

Diggers Seeds (Vic) – www.diggers.com.au
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: info@diggers.com.au

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

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

Tasmania

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

Four Seasons Herbswww.fourseasonherbs.com.au/shop/
Organically grown open-pollinated vegetable and herb seed.
Ph: 0412 721 268 email: sales@fourseasonsherbs.com.au

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

The Greenhousewww.thegreenhouseorganic.com
Organic vegetable and herb seed. Seed is also available from some retail outlets.
Ph: 0400 239 258 email: sales@thegreenhouseorganic.com

Eden Seeds (Qld) – www.edenseeds.com.au
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: enquiries@greenpatchseeds.com.au – 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.

Disease hosts

This is a good time of year to get a head start on weeding, as no-one likes weeding in hot weather. Leather gardening gloves or rigger’s gloves are great for weeding because they provide good protection from thorns, prickly stems, sharp edges of leaf blades, and insect or spider bites.
Weeds in the vegetable garden don’t just steal water and nutrients from your crops, many are also hosts to pests and/or diseases that can spread to your vegetables. By hosting diseases, weeds undermine your work at crop rotation to keep soil healthy.
Newly germinated weeds can be removed with a shuffle hoe, left on the bed surface, and covered with mulch. They will break down to return organic matter to topsoil. Small weeds that have not formed seed heads and are disease-free can be composted or put into worm farms. Larger weeds with seed heads must be removed and destroyed by burning, or soaking in water for an extended period, or disposed of in a sealed plastic bag. Remember the adage “One year’s seeds equals seven year’s weeds” – 15 years in some cases.
For gardening advice on removing troublesome perennial grasses and bulbous weeds, see my post on perennial weeds.

Nightshade (Solanum spp.)
The nightshade weeds are members of the same family as tomatoes, potatoes, capsicum and eggplant. Nightshade weeds (and Buffalo/Noogoora Burr) are hosts to Rhizoctonia fungi that can damage potato plants and tubers; cause collar rot in many plants, and cause damping-off in seedlings. They also provide a host to verticillium wilt that can affect a wide range of vegetables, fruit trees and ornamentals. Black Nightshade is a common weed in gardens. It grows to about 120 cm high, has groups of white (or purple-tinged) star-shaped flowers with a ring of 5 bright yellow stamens in the centre, and small green berries that blacken as they mature. Birds spread this weed by eating the berries.

Cobblers pegs (Bidens pilosa)
This weed is also known in Australia as ‘farmer’s friends’ because the barbs at the end of seeds allow the masses of seeds to cling to clothing and animal fur. Each plant produces hundreds of seeds and this weed can grow into dense stands that can quickly fill an entire bed. It is a host for root knot nematodes, tomato spotted wilt, and sclerotinia rot that can affect many crop plants. Remove and destroy these weeds while they are very small.

New seed catalogue

Greenpatch Organic Seeds have released their mail order catalogue for 2001-12. They have added many new Heritage vegetable, flowering annual and herb varieties to their range. They also have 230 varieties of potted plants, tubers and bulbs that can be delivered to you in all states except Tasmania and Western Australia. As Greenpatch is in our neighbourhood, I had a lovely time last week at Greenpatch browsing through their seeds, plants and books for things to add to my collection. Like us, Greenpatch is certified-organic with the Organic Growers of Australia. All their seeds are non-GM, non-hybrid and open-pollinated, so that you can save seed of your favourite varieties from your own crop.
You can ask for a catalogue by e-mailing: enquiries@greenpatchseeds.com.au or download a catalogue from their secure website.

Rust diseases

There are hundreds of types of fungi that cause ‘rust’ on plants but each type has a limited number of host plants so that your whole garden is not likely to be overrun by rust.
Rust can occur in various seasons but it does need moisture to grow. It typically causes yellow or brown markings on upper surface of leaves, and small yellow or brown powdery growths on the underside of leaves. The powdery substance consists of fungal spores that can be blown about by wind, infecting other plants that are susceptible to that type of rust fungus.
Below, on the left, are pictures of rust on the underside if a frangipani leaf and typical signs of rust on grasses. Some leaf markings can be confused with fungal diseases. On the right are pictures of hail damage on a cycad and spores on the underside of a fern frond – which is how ferns reproduce.

Treatment
Basically, rust diseases are a sign of malnutrition that produces an unsuitable pH on the leaf surface. Plants, like humans and animals, are more prone to diseases when they have a poor diet, and rust diseases can be avoided by keeping plants growing vigorously – but this is not always possible in extreme weather conditions. Sulphur or copper are the usual treatments for rust. Both of these are nutritional elements that can be supplied by various fertilisers, including seaweed extracts. Seaweed also contains plenty of potassium that strengthens cell walls, sulphur, and trace elements (including copper) that boost plants’ immune systems.
For mild cases of rust, remove damaged parts of the affected plant and burn these, or dispose of them in a sealed plastic bag. Don’t ever compost them, as the spores may not be killed. Then give the plant a foliar feed of seaweed extract tea and water some into the ground over the root area. Improve your fertilising program using a complete organic fertiliser.
For deciduous plants, rake up and dispose of dropped leaves to avoid reinfecting the plant. Apply the seaweed tea at bud swell.
For more severe cases, after removing damaged foliage, plants can be dusted with elemental sulphur (flowers of sulphur. However, as the spores are under leaves and the dust can be difficult to apply, affected plants can be sprayed with wettable sulphur in cool weather only, as sulphur will damage plants when temperatures are over 24 degrees Celcius. Be aware too, that sulphur will also kill pest predators. If these are present on affected plants, apply chamomile tea (one tea bag to 500 ml water) instead.