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Summer 2009 / 2010
The winter rains have been the best for many years and gardens (and gardeners) have responded, spring gardens have never looked better and there is still time to plant for Christmas and summer displays.
With the good soil moisture in most regions it is important to retain as much of this valuable moisture as possible and the way to do this is to mulch, mulch, mulch.
At this time of year the warmth and moisture cause weeds to grow rapidly and it is important to deal with them before they complete their life cycle and seed.
Nature abhors bare soil so any weeds will quickly reestablish if allowed to do so.
Mulching will help to prevent this and will reduce the amount of time which needs to be spent weeding and watering.
Mulching occurs naturally in nature, with leaves, twigs, spent flowers and grasses forming a protective covering which gradually decomposes to feed the soil and it is this natural process which we replicate when we mulch our gardens.
BENEFITS OF MULCHING.
Weed control… to control weeds in the garden mulches should be weed free and applied deeply enough to prevent any weed seeds from germinating.
Mulches insulate and regulate the temperature of the soil, keeping soil temperatures stable.
Mulches reduce evaporation, valuable soil moisture is retained for longer periods.
Organic mulches add organic matter to the soil as they decompose improving the structure and water holding capacity of the soil, improve soil aeration and the passage of water through the soil.
Organic mulches add nutrients to the soil and encourage earthworm activity.
The benefits of mulching apply to all soil types, the water holding capacity of sandy soil is improved and clay soils will gradually become more friable with the addition of organic matter.
Mulch reduces soil splashing, which helps to prevent soil borne diseases from coming into contact with plants.
Mulches prevent soil crusting, thus improving the absorption of water and reducing soil erosion and loss of top soil.
Ripening vegetables such as pumpkins, tomatoes, cucumbers etc are protected from direct contact with the soil and are less likely to rot or be attacked by garden pests.
MULCHING TIPS
More is not always better, mulch applied too thickly may shed water and cause the soil underneath to dry out.
Mulch should be porous enough to let water pass through and dense enough to prevent evaporation or weed growth.
Soils which have a low content of organic matter tend to repel moisture and wasteful “run off” can occur, if you have this problem a soil wetting agent applied under mulch will ensure better penetration and save valuable moisture.
Shake mulch and “fluff up”as you spread to prevent packing down.
Do not pile mulch around tree or plant stems, as this keeps moisture in direct contact with the bark and suffocates the layer of living tissue (the Phloem) which transfers food up and down the plant, resulting in an inability by the plant to take up sufficient water and leaf drop, root dieback and general decline occur.
Mulching around new plantings helps to keep moisture in the root ball until roots have established in surrounding soil.
Spoiled grass hay makes excellent mulch, however it often contains weed seeds which germinate when mulch becomes moist, if this occurs simply flip the mulch over.
Apply some blood and bone or other high nitrogen fertilizer under mulch to prevent temporary nitrogen loss, particularly with mulch which has not started to decay.
Soak new bales of mulch with water to kick start the process of decay.
MULCHING MATERIALS.
Grass Clippings
Good for mulching around seedlings and smaller plants as they are quite fine in texture.
Allow to dry slightly and apply in thin layers to allow moisture to penetrate.
Rich in nitrogen and contain some potash.
Pine Needles
Make an excellent mulch for the acid lovers in your garden. Use them around blueberries, strawberries, azaleas and rhododendrons.
Straw
A coarse mulch which is usually seed free as it only consists of the plant stalk.
An excellent mulch which does not pack down easily and allows rain to penetrate.
Wood Chips
Long lasting mulch for use around trees, shrubs and larger areas in the garden.
Decompose slowly and contain some nutrients.
Weeds
Use only weeds which are seed free, never use weeds such as couch or oxalis which spread underground or grow from bulbs.
Use where a coarse mulch is required, around fruit trees or shrubs.
Sawdust
Best left to weather until has become brown and crumbly.
Well rotted sawdust is a good soil conditioner which increases the water holding capacity of the soil, it has very little nutrient value.
Apply thinly as it packs down easily and will create a barrier which is impervious to moisture.
Never use sawdust from treated pine and similar products.
Manure
An excellent soil conditioner, nutrient value varies with age, storage and animal health.
Manures with a low nitrogen content are often referred to as “cold’ manures, e.g.(cow manure), while manures with a high nitrogen content are “hot” manures, e.g. (poultry manure).
Never apply fresh manure around plants and store under cover to prevent nutrient loss.
Pea Straw
A valuable, coarse mulch which does not pack down, an excellent soil conditioner which adds nutrients to the soil as it decays.
Sugar Cane Mulch.
Another good coarse mulch which is attractive in the ornamental garden, does not have any weed seeds and stays fluffy allowing rain to penetrate.
Leaf Mould
Another great soil conditioner, use around acid lovers or apply some lime or dolomite in general garden areas.
INORGANIC MULCHES
Inorganic mulches are usually plastic, fabric or stone, they do not contain weed seeds, rob the soil of nitrogen or decompose.
On the downside they do not contribute organic matter to the soil and are often expensive.
Plastic
Reduces weeds and keeps soil moist.
In areas where soil moisture is a problem plastic may keep soil too wet and dank and cause problems with root disease.
Has a tendency to tear and break down quickly.
It may be necessary to cover plastic with another mulch to prevent this occuring.
Water cannot penetrate plastic therefore holes need to be made in the plastic to enable water to reach the soil.
Fabric
Woven of fabric, plastic or paper they come in various lengths and widths.
Effective in reducing weeds and allowing water, air and fertilizers to pass through.
Stone
Crushed stone, gravel and pebbles…available in a wide range of colours, textures and materials.
Allow rain and irrigation to penetrate and give good weed control, however this can become increasingly difficult over time as soil, leaves, and other debris becomes trapped in the stones creating an ideal environment for seed germination.
Large areas of rocks can heat up and reflect heat onto plants during the summer months creating a hot micro climate.
 Difficult to contain and have a tendency to migrate to areas of the garden such as lawns where they can cause problems when mowing.
Of all the tasks that you do in your garden, mulching is one of the most beneficial, contributing to soil conditioning, fertilizing, weed control and water and soil conservation.
A well mulched garden can reduce your watering by up to 50 per cent.
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In Vegie garden plant climbing and bush beans, beetroot, broccoli,cauliflower,celery, cabbage, capsicum, carrot, cucumber, eggplant, kohlrabi, leek,onions, peas,swede turnip, turnip,lettuce, parsnip, pumpkin, rhubarb crowns, silver beet, spring onions, sweetcorn, tomato and zucchini.
Feed vegetables with a soluble fertilizer fortnightly to keep them growing strongly.
Watch for slugs and snail and aphids which will demolish seedlings very quickly.
Bush and climbing beans planted now will return large yields from a small amount of space if they are kept moist with a mulch.
Continue to harvest strawberries, feed and keep moist.
Potatoes which are growing strongly should have soil mounded around them to prevent the developing tubers from becoming green and inedible.
A thick layer of mulch will also prevent this provided it is replenished frequently as the potatoes will then form in the mulch.
With the arrival of warmer weather we tend to develop a craving for moist, crunchy salad vegetables. Picked fresh from the garden just before they are needed they are fresh, nutritious and tasty.
Lettuce is easy to grow and there are many varieties to choose from.
Hearting or crisphead types have tight heads which are slow to mature and the entire plant is harvested.This group includes Great Lakes, Iceberg and Yatesdale.
Butterhead lettuce a soft, smooth, semi hearting lettuce includes red and green mignonette which have soft curly leaves and a small heart and Buttercrunch which has compact crisp dark green heads.
Cos or Romaine has elongated heads of upright leave which form a loose heart, stiff mid ribs and a crunchy texture.
Leaf or open hearted lettuce are the easiest of all to grow, fast maturing and heat tolerant, they do not bolt to seed and individual leaves can be harvested over a long period.
Oak Leaf has several different forms, from pale green to brown. Red Coral and Green Coral have smooth leaves with heavily frilled margins. 
Lettuce enjoy fertile soil which has plenty of organic matter incorporated and is moist and well drained. If the weather is hot plant them in the cool of the evening and shade them from the hot afternoon sun until they are established.
Varieties which have red tinged foliage are more heat tolerant.
Moisture is important to produce sweet crunchy leaves, so mulch to conserve moisture.
Celery is easy to grow provided a few basic needs are met. Soil should be limed and fertile as celery will not grow in acidic soil.
Mulch heavily, water with a seaweed solution and keep moist for optimum growth.
Spring onions enjoy soil which has some dolomite raked into the surface, plant and cover with a thin layer of soil, water deeply and you will have a good supply for salads and stirfrys.
For those who want to try something a little different Crocus sativus, the saffron crocus, has stunning purple flowers which occur in mid autumn from amongst grass like foliage.
The flowers provide the stigmas which are dried and used in cooking for colour and flavour.
They like a cool wet spring, followed by a hot dry, summer and then a cool, moist autumn.
Use in rice, couscous and a range of soups, fish and middle eastern dishes.
The summer herb garden is always a delight and we have many herbs to enliven your summer salads and Christmas dishes. Choose from golden oregano, lemon verbena,sage, red sage, rosemary, chives, garlic chives, thyme, mint and and many more.
Give your herbs a sunny spot in the garden and you will have fresh flavours in the kitchen whenever you need them.
In the Ornamental garden potted plants will dry out quickly as the weather becomes warmer, ensure that the pot they are in is large enough and group them closely together in a spot which has morning sun or dappled shade, and mulch to keep roots cool and prevent evaporation.
Water storing crystals added to plants in pots should be first soaked in a seaweed solution to rehydrate them, before adding to the root zone of the plant.
Always follow the recommended amount on the container when using in pots.
Give your ferns a shady spot, keep them moist, and mist gently on very hot days to keep them green and happy.
Plant seedlings of petunias and other summer flowering annuals in bare spots where spring annuals have faded.
A slow release fertilizer will benefit all trees, shrubs, and other potted plants, remember to water well before and after fertilizing.
Divide congested clumps of bearded iris as flowering finishes.
Prune spring blossom trees and shrubs and once flowering roses after flowering finishes, water deeply and mulch.
Roses can be fed now with blood and bone or pelletised chicken manure and a handful of sulphate of potash, water in well and mulch.
 Clematis make wonderful partners for roses, the huge delicate flowers look superb twining amongst the roses and they enjoy similar garden conditions.
Clematis enjoy moist soil which has been enriched with compost or well rotted manure.
They like a sunny position with a cool root run, the best way to achieve this is with an organic mulch.
For a tough and undemanding hedge plant Pittosporum “Cut Above” is suitable for full sun or part shade, coastal planting, hedges, tubs and topiary.
Syzygium australe “Bush Christmas” has a compact habit which lends itself to shaping into a dense hedge, unpruned it will grow to 2-3 metres however with regular pruning it can be kept to 1 metre.
In winter it is covered with a flush of orange new growth.
Bush Christmas will make a great container plant and will be happy indoors for a short time decorated for the festive season.
In the Native garden Callistemons have been looking wonderful, trim them and other spring flowering native plants back as flowering finishes, this improves flowering, keeps bushes shapely and extends the life of the plant.
Callistemon “Firebrand” has bright red bottle brush flowers during spring and autumn.
Correa “White Tips is a very attractive and hardy shrub which has long red tubed flowers with recurved white lips, to 65cms high and 60 cms wide it will grow well in rocky to poor soils where many other plants will struggle.
 Pimelea “Silver Ghost” is a very pretty small plant which has clusters of small white flowers in spring, hardy and reliable.
Grevilleas are hardy plants which will beautify and bring native birds to the garden, for success with grevilleas good drainage is essential, in gardens where water is not readily dispersed raising garden beds will solve this problem.
Grevilleas prefer a sunny aspect, an acid to neutral soil and sandy soils will benefit from additional compost or organic matter as very sandy soils will result in sparse foliage and flowers.
Water both plant and garden bed well before planting.
Dig a hole which is as deep as and twice as wide as the pot which contains the plant and loosen the soil at the base of the hole.
Tap the plant out of the pot and trim any coiled roots, place in the hole, backfill and firm well.
Water in thoroughly and mulch.
Do not over fertilize as this will often result in the death of the plant and always use a low phosphorus fertilizer.
Pinch out the growing tips for the first year or two and trim immediately after flowering to keep the plant shapely and to prolong life.
 Grevillea “Winpara Gem”is a very attractive shrub which has deep red spider flowers with attractive gold tips, another spider grevillea is the very attractive G. “Ellendale”, a quick growing shrub, to 2m high and wide, which has large pendulous clusters of flowers during autumn, winter and spring. Good for coastal planting. 
For those who like gold tones G. “Apricot Charm’ has beautiful clusters of deep apricot flowers and is fast growing and hardy.
Grevillea “Superb” is a long lived and hardy plant with bright green, deeply divided leaves, and huge red spider flowers.
Grevillea “Lady O” is a medium sized spreading shrub which will produce bright red flowers all year round under mild conditions and is ideal for attracting nectar feeding birds to the garden. Prune regularly and use a low phosphorus fertilizer. “Ember Glow” is another attractive spider grevillea with brilliant red flowers tipped with gold.
In the Orchard citrus can be planted now if a few basic needs are met.
A sheltered sunny spot is essential as citrus will not thrive in exposed, windy sites.
Citrus require a well drained soil which is rich, well aerated and moist, they are gross feeders and should be fed regularly with a specific citrus food or complete fertilizer.
This should be applied out to the drip line or outer edge of the tree.
Keep grass well away from the trunk as grass robs trees of the nutrients they need.
Citrus adapt well to growing in pots and containers and make handsome and decorative subjects for a warm outdoor living area.They need a well drained and aerated potting mix and must be kept well watered and fed when in active growth.
Citrus rarely need special pruning and a light trim of straggly growth is all that is required.
A tendency to scale and sooty mould are easily controlled with soft soap and oil sprays.
We have a large range of citrus at the nursery including Imperial Mandarin, “Seedless Valencia” Orange, Meyer and Lisbon Lemon, Minneola Tangelo, Calamondin, Red and “Marsh” Grapefruit and the Tahitian Lime.
Olives are small strong trees which need little support, they prefer a light, lime based soil and are suited to areas with hot, dry, summers and cold, wet, winters.
These attractive small trees are often overlooked, which is a pity as their long dark leaves, silvered underneath, are a perfect foil for many garden plants.
A small grove of olives underplanted with lavender will beautify that tough spot in your garden, provide you with olives for pickling and demand little in the way of attention or water.
Plant in full sun in well drained soil, although drought hardy they will benefit from regular watering.
For a graceful medditteranean touch in a sunny courtyard, olives grow well in containers. Unlikely to be very productive in this situation they are best regarded as ornamentals.
Olives bear on the previous season’s growth, remove any diseased, dead or crossing branches in late winter or early spring.
We have a good selection of trees in varying sizes so pop into the nursery and have a look.
Keep currants, raspberries, and other bramble and bush fruits well watered and deeply mulched, and apples and stone fruits mulched, band apple trunks with cardboard to trap codling moth.
Well that’s it for this month, enjoy the long summer days in the garden,
Marg and the Team at Meredith Nursery.
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