Bees and lavender

Beelavender Bees love lavender, and because French lavender* flowers during winter, it provides them with nourishment when there is little else in flower. Lavender is known for its calming effect on people and it has the same effect on bees. A hardy plant, French lavender prefers a gravelly soil with a close to neutral pH. It is an efficient water user and requires little complete fertiliser, suits warmer climates, makes an attractive hedge, and is happy in beds or a large pot. All it needs is a light hair cut when flowering has finished.
Bee numbers are declining around the world. This is a matter for concern for all of us as we rely on bees to pollinate a good number of our fruits and vegetables. As well as growing some French lavender or some winter-flowering annuals, please ensure you keep some clean water available in your garden as bees need clean water, too. Many drown each year from trying to drink chlorinated pool water. A bird bath or large plant saucer, regularly topped up with clean water, is all they need.
* French Lavender (Lavendula dentata) is also known as Toothed Lavender, so named for the edges of its leaves.

Spring bulb reminder

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.

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

One of our readers, Sam, has shared some photos of his very successful efforts.
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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.

New concrete near trees

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.

Taking cuttings

Smhdwdcuttings2Summer is a good time to take semi-hardwood cuttings of your favourite evergreen perennials to add to your garden or share with friends. 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 lids will be removed to allow some ventilation.

Frangipani in Victoria

Now is the perfect time of year to take Frangipani cuttings

frangwht1 Bill has e-mailed me about growing Frangipani in north-west Victoria – and his question may be of interest to other readers.
Frangipani trees are tropical plants, and your area of Victoria is not an ideal climate for them, because minimum temperatures for most of the year are not high enough. Plants grown outside a suitable climate zone are more prone to diseases. There can be, within climate zones, microclimates in protected areas where temperature variations are not as extreme as those in the general area, and plants that need warmer conditions can be grown in these positions – if you prepared to give them extra care through autumn, winter and spring.

The only variety you could possibly grow is the hardier white Frangipani, and you would need to grow that in a position that is protected from wind, and against a north-facing brick wall where the thermal properties of the bricks keep the air around the plant slightly warmer at night. If you find someone in your area who is successfully growing a white frangipani, and is prepared to give you a cutting, now is the perfect time to take frangipani cuttings. See my post on how to prepare frangipani cuttings for planting.

Otherwise, I think it might be wiser to choose a different tree that is more suited to the local climate.

Wollemi pine update

wollemi pine 2The recently discovered Wollemi pine was a topic of discussion on the Don Burke gardening radio program recently. This fossil conifer has been a source of considerable disappointment to many gardeners since its release. One could reasonably think that a species of tree that has survived for 200 million years, according to the accompanying care guide, would be fairly hardy, but this is not the case. These trees cannot handle heavy rainfall, drought, or full sun. They are easily stressed, and prone to phytophthora root rot, as well several other soil diseases.

The tree I received last Christmas was soon re-potted into a slightly larger container with some coco peat, compost and worm castings as fertiliser, and a little coarse river sand. After re-potting, the tree was positioned on a verandah on the northern side of our house, but it quickly became apparent that it was not happy in a warm environment, and was transferred to the verandah on the south side where it has survived, but has made only a couple of centimetres growth. The care guide gives no real indication of the species’ fussy moisture requirements other than the vague advice to “check moisture levels regularly”. Neither did the care guide state that soil in the area where the trees were discovered could have a pH as low as 4, which is too acidic for most plants to survive, or that a coir supplier had developed a special potting mix for these trees.

Don said that little information on the species had been available, resulting in the death of a lot of purchased Wollemi pines, and asked a spokesman from Sydney’s Botanic Gardens why the tree had been released for sale prematurely. The spokesman’s response was that it was to prevent people from damaging the discovery site when attempting to obtain a specimen of these trees. This reasoning would be easier to accept if they didn’t charge such exorbitant prices for these pines.

My advice, if you would like to grow a Wollemi pine, is to visit the web site below and find out if you can provide suitable conditions for this plant before outlaying any money.

Transplanting Frangipani

Glen, in Melbourne, wants to know the best time to transplant a well-established frangipani tree from a pot to the soil, and should he do anything to the soil. The best time to transplant Frangipani is at the end of winter, while the tree is still dormant but close to breaking dormancy. In Warm climates, this can be done from the second week in August (during a Full Moon phase) but, as Melbourne has some more cold weather to come, Glen would be wise to wait until early September. Before planting any tree it is wise to check soil drainage, and this is extremely important for Frangipani as they won’t tolerate wet feet. (See Planting trees ) If soil is on the heavy side, some coarse river sand can be mixed through the soil used to fill the hole. The hardest part about transplanting Frangipani is getting them out of the pot because their roots are very brittle and can snap off if jolted, especially if the plant is large. If the tree is in a plastic pot, the safest way is to cut the pot away to remove the tree. If the tree is in a very sturdy pot, run a piece of wire around the inside rim of the pot to loosen the root ball, or hose gently around the inside edge of the pot. Then gently turn the pot on its side and ease the tree from the pot. If the pot has a large hole in the base, a broom handle or dowel can be used to gently push the root ball from the base. After settling the tree in its new location, water gently to settle the soil but do not tramp the soil down. Apply a 5 cm layer of mulch when soil has warmed, keeping mulch clear of the trunk to avoid collar rot. Although the Frangipani is very drought tolerant, the tree will need regular watering until established. Water when the top cm of soil is dry.

Rose planting time…

rdrose2Some nurseries are advertising bare-rooted roses for sale. This is just a reminder to, if possible, avoid purchasing bare-rooted roses before the end of June, as roses that have been lifted before they are fully dormant do not usually grow well.
Potted roses can be planted as soon as they are dormant, if your area is not prone to severe frosts.
For rose planting guide-lines see: here
Planting shrubs and vines