July and August are ideal months to get a head start on weed control. Last Quarter phase is a good phase for weeding because seed germination tends to be lower then, and you are less likely to stimulate further weed seed germination while removing weeds. Many weeds that germinate in cultivated soil are and pests that damage vegetable crops. July is too late to eliminate the lawn weed Bindii as the spiky seed heads will be starting to form.
You can find organic treatments for troublesome weeds in the ‘Weeding Between the Lines’ category on this blog.
When spring bulbs have finished flowering, don’t forget to allow the foliage to die back before lifting bulbs. It is important to leave the foliage because the yellowing and fading occurs as the plants withdraw nutrients from the leaves to store in the bulbs for next season’s growth. Depriving spring bulbs of this essential part of their growth cycle will result in poor, or no, flowering next spring.
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
One of our readers, Sam, has shared some photos of his very successful efforts.
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.
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.
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.
I have received an e-mail from a reader who is concerned about her neighbour’s plan to put a screen fence about 35 cm from the base of her beautiful frangipani tree, because the fence posts must be set in concrete and doesn’t know the size of the tree’s root ball or if it will damage the tree.
As new concrete near gardens is a common problem for gardeners, I am posting my answer on my blog rather than merely giving a private reply.
Generally, the feeder roots of shrubs and trees are located under the outer edge of the plant’s foliage in what is called the drip-line. Nature designed plants this way so that rain (and bird droppings, mineral dust etc.) running off the foliage falls where water and nutrients can be taken up quickly by the feeder roots (see diagram).
There are some exceptions to this rule as roots of umbrella trees, figs, crepe myrtles and liquidambers, for example, can wander all over the place in search of water. Usually, when trees or shrubs are severely pruned back, they will produce new feeder roots below the new drip-line and this can be helpful in preparing to move large shrubs and small trees.
New concrete contains lime that makes it alkaline, and hydrated lime (brickie’s lime) that is used in concrete will burn plant roots and should not be used on gardens that contain plants. If you are unable to avoid using concrete for walls or footings near established trees or shrubs, you can ask the builder to line the hole with strong plastic sheeting to prevent the new concrete coming into contact with plant roots. Plastic degrades in light but not in soil.
Adding plenty of mature compost to topsoil before planting trees and shrubs will help protect plants from the adverse effects of new concrete as one of the functions of compost is to buffer plant roots from unsuitable pH levels in surrounding soil. Where plants are established before concrete is used, adding a 5 cm layer of mature compost to the drip-line area, and covering it with 5 cm of organic mulch will help your plants. Remember to keep compost and mulch well clear of the trunk.
A more serious concern is where the concrete is to support a wall or fence close to established plants and the trees and shrubs need to be pruned on the side closest to the wall, as timing is important. Some plants, including frangipani, bleed a lot of sap if pruned when they are not dormant. The very best time for this type of pruning to reduce “bleeding” sap, is to prune during Last Quarter phase of the moon. For these plants, the wall or fence should be constructed during winter when the affected trees and shrubs are completely dormant. However, if a shrub or small tree requires a lot of sunlight or warmth for good growth, and the proposed structure will prevent this (i.e. the plant will be on the south side of the structure), it may be best to move the plant during winter for deciduous plants, or in autumn for evergreens, to a more suitable spot or into a large tub, if space is limited.
In the case of frangipanis, these lovely trees are often seen growing against north-facing walls of houses. Once concrete has seasoned, it does not seem to bother them, and they love the warmth that is stored in the wall during the day and slowly released at night.
April is a good time to plant garlic in most areas. Garlic needs a soil that is rich in humus but doesn’t require a lot of nitrogen so avoid adding manures to the bed. Uncomposted manures can cause garlic bulbs to rot, although processed poultry fertiliser is quite suitable for garlic. Garlic needs a full range of plant nutrients and trace elements for healthy growth. A drink of seaweed extract tea over the whole planting area will supply a full range of trace elements. Garlic also needs a soil pH of that is close to neutral. Working a 5 cm layer of well-made aerobic compost into the topsoil will help to buffer the cloves from an unsuitable pH in surrounding soil.
We always sow garlic (and other bulbs) during Full Moon phase. That is from the 19th to the 24th of this month. Gardeners in areas with very mild winters can put the cloves (in a plastic bag) into the vege crisper of the fridge until then – because garlic likes a bit of a chill before starting to grow. As garlic needs dry conditions at harvest time, sowing in April usually allows the bulbs to mature before wet weather in late spring–summer.
Sow each clove (pointy end up) in a 5 cm deep hole, and water thoroughly. If sowing large quantities, place them 15 cm apart. Don’t forget to mulch the bed afterwards because garlic plants don’t like competing with weeds.
Summer is a good time to take semi-hardwood cuttings of your favourite evergreen perennials to add to your garden or share with friends. And, as you can see from the moon planting panel on the right side of the page, the Full Moon phase is best for this job as root growth establishes more quickly when cuttings are taken in this phase.
Semi-hardwood cuttings are sections of stem that have stiffened enough not to wilt easily. Cuttings should be at least 10 cm long and contain about 5 nodes, so that at least 2 nodes can be covered with mix, and you have two sections for growth. A node is a joint in the stem where leaves or roots can form – and indicated by a line on the stem or a leaf scar. Pinch out the very tip of the cutting, and leave foliage on the next two nodes, then carefully remove foliage from the lower nodes and trim the cutting just below a node. (You will find a lot more detail about preparing different types of cuttings in Easy Organic Gardening and Moon Planting.) Then poke the cutting into a pot that contains organic potting mix with some washed river sand added to ensure easy drainage.
This week, I’ve been taking cuttings of thyme, rosemary, Arabian jasmine, zonal geraniums and some Hawaiian hibiscus varieties. We replace our commercial perennial herb plants every three or four years because younger plants produce the best growth for harvesting.
I cut the remaining leaves in half on geraniums and hibiscus (and any plants with large leaves) to conserve moisture in the cuttings, but leave some leaf material to photosynthesise (make energy to grow). Dipping the base of the cuttings in certified-organic honey can help stimulate root growth – you only need a teaspoonful in a shallow dish. I water the pots with an organic liquid fertiliser and poke the cuttings into the mix against the edge of the pot as it helps support the cuttings. The cuttings are kept consistently damp in a warm spot out of direct sunlight until they have formed roots and are ready for putting in individual pots or planting in the garden.
Most experts recommend that cuttings should be covered. However, we have found that the perennial culinary herbs, lavender, and a lot of plants with furry leaves don’t like the humidity provided by a cover. However, the pots of jasmine, hibiscus get covered with a large plastic juice or soft drink bottle with the base removed and the lid intact. At the first sign of new growth the leads will be removed to allow some ventilation.
If you want to take semi-hardwood cuttings of abelia, box, bougainvillea, callistemon (bottlebrush), carnation, clematis, daphne, grevillea, Hawaiian hibiscus, jasmine, NSW Christmas bush, pelagonium (geranium), lavender, margoram, oregano, rosemary, sage or thyme, the Full Moon phase this month extends until noon on 26th January, and from 19th to the 24th next month.
A recent article published in BFA’s electronic newsletter, The Organic Advantage, quoted recent US research comparing organically-grown strawberries with those grown by conventional methods. Not surprisingly, the organic strawberries came out best for flavour, nutritional value, health-protecting antioxidant levels and colour, and stayed fresh for longer. The research was conducted across 26 farms and concluded that, not only was the organic fruit better, but the soil on the organic farms was higher in carbon and microbial activity, and had higher concentrations of trace elements. Soils on organic farms were also 30% higher in nitrogen than soils on conventional farms where synthetic nitrogen fertilisers were used.
There is nothing like the taste of organic strawberries. This probably has a lot to do with the fact that organic strawberries do not contain residues of the systemic pesticides and fungicides that are used on conventionally-grown strawberries.
I remember reading that strawberries were first discovered growing at the edges of pine forests in the northern hemisphere. This fact indicates three things, – that they will appreciate some shade from Australia’s intense summer sun; that they prefer a soil that is on the acidic side, and that they are dependent on mycorrhiza fungi in soil to assist them to absorb nutrients and moisture. Mycorrhiza-dependent plants absolutely thrive in organic cultivation because the humus in organic soils provides a habitat for beneficial mycorrhiza fungi.
When your strawberry plants start to flower, give them a drink of seaweed extract diluted to weak black tea strength. Kelp provides a good supply of potassium and a range of trace elements that are important in the formation of sweet fruit. The potassium also strengthens plant cells to improve disease resistance. Eco-cweed, Acadian, and Natrakelp are all products registered for use on organic gardens.
Water plants early in the day, too. Wet leaves at nightfall provide more suitable conditions for fungal diseases to establish.