thisplace.com.au - Gardening and Landscaping Questions and Answers

Gardening and Landscaping

Here are some gardening and landscaping questions that have been asked and the answers that some of our experts have responded with.

Turf & Lawn Topics

(14/07/2001) - What is the best Lawn to grow ...
(05/04/2001) - Turf Information

Landscaping Topics

(19/07/2001) - Better landscaping
(14/05/2001) - Rubber Liner for Waterfall and Pond
(26/03/2001) - Backyard Drainage System
(23/02/2001) - Clay Soil
(24/01/2001) - Create a rainforest garden

Weeds, Pests & Problems Topics

(24/09/2001) - Wisteria Plant Root Concerns
(29/06/2001) - Nut Grass Problems
(22/04/2001) - Stopping Possums Eating Leaves
(11/04/2001) - Azalea Fungus and Insect Problems
(20/03/2001) - Bracken Ferns
(10/03/2001) - Palm Tree Leaves Going Brown
(02/01/2001) - Thai Eggplant probems
(02/01/2001) - Green Grubs eating leaves of Rosella Plant
(28/11/2000) - Plagued by neighbourhood cats

Other Gardening Topics

(19/07/2001) - How and when should I prune a croton
(17/04/2001) - Vegetables and Annual Plants

Q: I have recently planted a young wisteria plant in my front garden - with the aim of training it along our verandah, however I am concerned about the proximity of it to the brick work and the damage (if any) the roots may cause.

Would you please advise if the roots of the Wisteria will become uncontrollable and search and ruin the driveway (which is close by) and the brickwork of the verandah.

I have an alternative location - which is away from all the temptations - however I'd really like for it to be where it is out the front.

A: The vine itself is quite vigorous and will need a strong support to keep up with its fast growth. Wisteria can grow up to 10 feet a year, especially once it's established in the proper environment. Wisteria performs best in deep, moist, but well-drained soil that is neutral to slightly alkaline.

Wisteria can get down into sewer pipes, if that is what you are referring to. The roots are thin and fibrous and may penetrate hairline cracks. They run deep and far. If you have underground pipes near where you want the plant to grow, you may be concerned, but it would take years for the wisteria roots to do any damage.

Otherwise, keep it in its pot to protect your pipes, etc if you are worried. But, remember to pot up in size as it enlarges, giving it fresh potting soil with organic material.

Q: How and when should I prune a croton?
Mine are getting straggly.

A: Crotons with their colourful, glossy foliage and variation of leaf types are one of the most popular plants around the world. It is a native of the tropics from Java to Australia and the South Sea Islands, and because of its susceptibility to cold injury, is restricted to the southern and warmer parts of central Florida. Cold injury normally shows as leaf dropping soon after periods of cold weather.

Crotons may be pruned heavily during spring or other mild periods of the year. Crotons may attain a height of 8-10 feet , and tend to produce the heaviest foliage at the top of the plant. It is wise to cut back rather heavily to force new foliage lower down on the stem. It is best to prune about one-third of the branches, then wait until new growth has started before pruning again. This keeps the plant more uniform in shape and more attractive during the pruning process.

Crotons are easily propagated from greenwood cuttings, leaf bud cuttings, or if plants are desired quickly, by air layering. Make your cuttings from 4-12 inches in length and insert them in sand or peat, or in a mixture of the two, for rooting. In air layering, a ring of bark is removed from the branch to be layered, from two cuts spaced from one-half to one inch apart, exposing the wood. The cambium layer, a slight green area immediately underneath the bark, should be completely removed to prevent new bark from forming again rather than roots. Wrap the cut surface with a ball of moist sphagnum moss about as big as a man's fist. This is held in place with a waxed string or rubber band and the entire ball wrapped with plastic film or aluminium foil. The plants will root quickly at the point the cut was made, and after the roots are established, the branch is removed from the parent just below the roots, and planted in a pot or in the garden where it is to grow.

Crotons develop their best leaf colours when planted in full sun. Plants spaced in shade or semi-shade tend to develop a large amount of green colour. Soil should be enriched with compost, muck, or peat moss, and the plants fertilised regularly with a general purpose fertiliser such as 6-6-6 or 6-4-8 three times per year.

The pests they are susceptible to are scale, mites, thrips, and root rot diseases.

The plants are large, but seldom grow to more than 15 feet and can be controlled by tip pruning to limit their height and promote bushy growth. When fast-growing varieties of croton become 4 to 5 feet high, they begin to lose their lower leaves, particularly if they aren't getting enough water. When this happens, you can prune them to within one foot of the ground and then fertilising and watering thoroughly. This will cause horizontal drooping branches to form. When pruning hedges try cutting each branch individually some distance below the desired height rather than using hedge shears.

The university recommends two cupfuls of a balanced fertiliser such as a 10-6-6 formula, for each mature plant, well-watered into the soil about every four months. 'In many island gardens, spraying the leaves with liquid fertilisers, applied according to the manufacturer's instructions, will help considerably to rejuvenate neglected crotons. The presence of trace minerals, particularly magnesium, zinc and copper, is thought to be important for good leaf colour, a circular suggests.
(19/07/2001)

Q: In a few more weeks I'll be moving to a house that has a front yard and a patio with overgrown and burnt grass and also bushes that are blocking my view, my question is what can I do to better my landscaping?

The first thing you must consider is how much you can or are prepared to spend on your garden/front yard. You can spend a little and make it look reasonable and develop it as you go or you could spend more and get an established look straight away. The choice is up to you.

Another thing to ask yourself is to think just how much time you want to spend in the yard, do you have a "green thumb", etc. This is important as it can influence the type of plants, features and grass you may want to use in the layout.

With these thoughts in mind possibly the best thing to do would be to go to our landscaping section and have a look at some of the ideas and then you may have an idea of which way you want to go. Each layout you choose will have it's own benefits and drawbacks but you will find that by having a think about what you want to get out of your garden you will choose the right option. The best thing is that if you do not like something you can always change it.
(19/07/2001)

Q: We have nut grass coming through the mulch around our fruit trees. We Roundup quite often but it keeps growing back. Is there an answer or do we have to start again?

A: After speaking with our Gardening expert from Perrott's Nursery Enoggera, they have given us a couple of ideas that you may be able to use.

1. Keep on spraying, as when you spray you only kill the one nut at the bottom but there are more that grow on either side and once the main one has been killed off then another one takes over and shoots.

2. Dig it up and take all the nuts out of the ground. The easiest way to dig up is to make the ground slightly damp as it makes it easier to pull out.
(29/06/2001)

Q: I would like some information on what would be the best Lawn to grow in this area? I was swaying towards maybe a winter green couch. Also how far does a large bag of seed go & how much is it?
Location - Scone, Hunter Valley NSW
Conditions - Frosty in Winter, 30-40 degrees in Summer

A: With the winter green couch it will discolour if the temperature drops below 5 degrees -C. SO you may have to think about that considering the area you live. There are some others that you could also consider.

Palmetto (Patented Turf) - is a new release, very popular throughout the U.S.A. This turf is a vigorous grower and light green in appearance. Palmetto is very versatile, being shade, cold and drought tolerant and is good in heavy traffic areas as it recovers well from damage.

Palmetto (Patented Turf)Sir Walter (Patented Turf) - developed in Australia for tough and cool conditions. It is resistant to most pests and diseases, retaining colour in many areas during winter. It tolerates partial shade, but grows best in full sun and sandy soil. It is good for the home garden with it's soft leaf and deep green colour. Recovers well from wear or mowing damage.

There is a new lawn available, Riley's Super Sports, which is a couch lawn. It stays green in winters, tolerates traffic and requires little mowing. The lawn is fine textured and requires little care to keep it looking good.
(14/05/2001)

Q: Where do I buy the rubber liner needed to line the waterfall and pond I propose to build and what size does it come in?

A: Probably the best place to purchase pond liner from is from a water garden specialist or an aquatic plant supplier. Also consider aquarium shops as they will often be able to supply you with what you will need. Our gardening expert Bruce Perrott also deals in water features and would be able to help you out - you can buy the liner for whatever shape and size that you will need. Remember to buy a little more than you need as too much is better than not enough.

Perrott's Nursery is located a 71 Elkhorn St Enoggera - ph 3355 7700.
(14/05/2001)

Q: Is there any environmentally sound way to prevent possums eating the leaves of two large mango trees in our garden. One is now completely leafless, and other becoming like it, with all new shoots and blossoms consumed? They are trees 40 years old.

A: After some research I have been able to come up with a couple of options for you to try.

1. Chinese Herbalists can make up Chinese tea concoctions which can be used to spray over the tree's, as they sound like large tree's this may not be an easy approach.

2. Possums do not like moth balls and so by placing a number of them around the trunk of the trees this should deter them from climbing up.

If neither of these options work then there you could contact Ken from Chemical Enterprises who may be able to provide you with meshing or some sort of barrier to stop them getting up the trees. You can contact them on (07) 3274 2330.
(22/04/2001)

Q: I grow vegetables and annual plants from seed, they often die while still only two leaves high. What am I doing wrong?

A: Your seedlings are most likely dying from a post emergent disease known as damping off. This disease is caused by fungus parasites that enter new seedlings where the stem grows from the soil. To avoid damping off, start with a clean or even sterile growing medium. Good air circulation is also important, so don't crowd your seedlings. Water with lukewarm water as cold water will cause undue stress to seedlings. Better still, water with chamomile tea! Chamomile tea is a concentrated source of calcium, potash and sulphur, which is a natural fungus fighter. Or water with Condy's crystals; a pinch to a bucketful, turning the water a burgundy red, should be sufficient.
(17/04/2001)

Q: My Azalea's are getting a light brown fungus on the underside of the leaves also a few leaves are starting to curl over with an insect of sort in the rolled over section. Could you please suggest a remedy for these problems. Last year we had a large problem with leave mould. Our garden is approximately only 20 month old.

A: More than likely it is insect damage that your Azalea's are suffering from. Damaged leaves can take on a silvery appearance and often there are little brown spots on the underside - with a magnifying glass it is possible to see the little lace fly. Two spotted mite, thrips and Azalea lace wing are the main problems.

Take some leaves to your local nursery for their opinion or start a spray program. Spraying for these problems must be done regularly from mid spring right through until mid to late Autumn.

Yates Mavrik is a chewing and sucking insect spray that is of low toxicity. You will have to spray fortnightly on both sides of the foliage. If this proves unsuccessful, then change to a stronger spray, such as Confidor, Roger, Folimat or Lebaycid.

Remember to take at all times when spraying. Pest Oil is non toxic and is registered for the control of 2 spotted mite.

These hints have been provided by Perrott's Nursery and the Greengold website.
(11/04/2001)

Q: I'm inquiring about turf, we live in Brisbane on the North side. Our block in the world is made mostly of shale and clay type soil, in fact I would not actually say we had any "soil"! I have lots of allergies and would prefer not to have a buffalo type grass. I need help with deciding what to buy I have no idea.

A: You would have to do a bit of work on your soil to help the grass grow. A good top soil would help.

There is a new lawn available, Riley's Super Sports, which is a couch lawn. It stays green in winters, tolerates traffic and requires little mowing. The lawn is fine textured and requires little care to keep it looking good.

Advantages:

mostly horizontal growth and so even in summer it may only need mowing once every few weeks.
recovers quickly from damage
very low seed head production and infrequent flowering which makes it good for allergy sufferers
drought tolerant
tolerant of heavy wear and traffic
the most shade tolerant of all the couch lawns
quite cold tolerant, staying reasonably green in winter even after frost if kept short and well fed coming into winter

Care and Maintenance:

well drained site
should be laid on 100-150mm (4-6") of sandy loam which is especially important in a shaded position
feed small amounts of fertiliser regularly
always mow to the same mower height setting regardless of how much leaf is removed

Lawn Renovating - What to do:

Description
When lawn quality is unacceptable, renovation may be necessary. Usually lawns with less than 50% weeds can be renovated and over seeded without tearing it up. Before renovating a lawn it is important to consider why the lawn had deteriorated in the first place and how this can be remedied.
When to renovate
The best time to renovate is in Autumn when environmental conditions are favourable and weed competition is much lower.
Basic Steps For Renovating a Lawn

Soil test - is recommended
Weed control - remove existing weeds.
Aeration - to improve drainage
Fertilising - slow release starter fertiliser
Seeding - by hand or spreader
Top dressing - to restore levels
Irrigate - lightly for soil to remain moist.

(05/04/2001)

Q: Our back yard In Tingalpa consists of 3 inches imported soil then thick clay and rock. In case it one day rains buckets, we want to install a drainage system. Three questions:

Is agricultural pipe the best system?
What is the proper way to lay it?
Who does this sort of work in this area and what does it cost?

A: Thank you for your enquiry and I am pleased to offer you the following information, which was provided by Sunshine Coast Geotechnical Manager, Rob Harris.

Without seeing the site it is hard to offer the correct solution.

If the clay is very plastic (ie. it doesn't let water through easily) then when the soil becomes saturated water does not flow away easily. You can install what is called "subsurface drains" which comprises of a 75mm diameter slotted agricultural pipe surrounded by coarse gravel in a trench approximately 300 - 450 mm wide which is drained to an outlet such as stormwater pit or somewhere the water can flow to. To be effective and depending on the size of the yard spacing at approx every 4-5 metres.

Plumbers can install these but the simple handyman can do it himself, pipe is available from hardware stores and gravel from landscape suppliers . If there are a lot of trenches required hire a bobcat for a couple of hours, its easier than hand digging , he can take away the excess clay, and put the gravel into the trench, and then backfill the trench with the removed topsoil and trim everything.

A quick trip to a hardware store will determine the agi pipe posts, and a phone call to the landscape suppliers to find out how much 10mm gravel costs will quickly determine the inputs, allow a couple of hundred for the bobcat.

I am able to provide some technical assistance if required, FREE of charge for first 30 mins on site, or we can offer a full design service and arrange a contractor if required, we are happy to provide a cost estimate for the work.

You can find my details online at thisplace.com.au just by doing a products and services directory search or just click here.
(26/03/2001)

Q: Is there a way of getting rid of Bracken Fern permanently? I am trying to clean up about one acre for landscaping.

A: After speaking with our experts at Perrott's Nursery, Enoggera, the best way to eradicate bracken fern is by spraying with Roundup. Just make sure you check the label and follow the instructions.
(20/03/2001)

Q: I have a palm tree that is going brown on the tips of the leaves. I water it every day. It is in full sun most of the day. I fertilise it with Miracle Grow.

A: Without knowing whether the palm is in the garden or a pot or what type it is, the information I can give you is that if it is in a pot then it may be getting too much water being watered every day. If it is in the garden, it is a possibility that it is a shady palm and needs to be taken out of the full sun.

If you would like more precise information and help you could either email me again with answers to What type of Palm? and Is it in a garden or pot?

This information was provided by Michael at Perrott's Nursery Enoggera.
(10/03/2001)

Q: Our back yard In Tingalpa consists of 3 inches imported soil then thick clay and rock. In case it one day rains buckets, we want to install a drainage system. Three questions:

Is agricultural pipe the best system?
What is the proper way to lay it?
Who does this sort of work in this area and what does it cost?

A: Thank you for your enquiry and I am pleased to offer you the following information, which was provided by Sunshine Coast Geotechnical Manager, Rob Harris.

Without seeing the site it is hard to offer the correct solution.

You can find my details online at thisplace.com.au just by doing a products and services directory search or just click here.
(23/02/2001)

Q: I am wanting to create a rainforest in the lower section of my yard. The area is in full sun in the morning and shade in the afternoon. There is a large Jacaranda in the middle of the area, palms that have just popped up and lots of ochna which we are slowly poisoning. The soil is clay or rock so we aren't having much success with plants surviving there. We have planted lilly pillies, golden pendas, ivory curls and 2 tree ferns which have died. We have also installed a drip irrigation system to each plant. Some have survived but aren't that healthy. What plants would survive in this sort of soil and how can we bring back to life some of our failures. We are thinking of a leopard tree or fig tree. It is quite a large area.

A: We spoke to the experts at Perrott's Nursery Enoggera (Ph 07 - 3355 7700 ) and they said a big problem this summer has been a lack of water, and this could be your problem - because it has been so dry there may not be much sub soil moisture and any that is there is probably being taken by the Jacaranda - they suggested long deep watering for at least 20 minutes to allow the water to penetrate and soak the soil. Clay can be broken down with the new type of clay breakers that you simply attach to your hose and water in.

The traditional method of breaking down clay is to incorporate lots of organic matter into the soil and to add gypsum This changes the soil structure from big clods to a fine, easily worked texture which makes gardening easier and improves drainage. Gypsum also releases minerals within the soil structure from the clay particles so that they become available for plant nutrition. It is important to use natural gypsum, not the white builder's gypsum, for this purpose.

However, not all clays respond well to gypsum. To find out which ones do, a simple test known as the Emerson Dispersion Test can be done.

Drop a piece of dry soil aggregate, about 6mm across, into a glass of rainwater. Don't move the glass - just watch what happens to it after an hour and then after 24 hours. If it slowly disperses into the water, first forming a halo of clay particles around the aggregate, it will respond to the addition of gypsum to the soil. If it does nothing at all in the water, it would be a waste of time adding gypsum to the soil as it won't respond. The greater the cloudiness of the water and the more rapidly it develops, the greater will be the benefit of adding gypsum to the soil and the higher the amount needed.

It's a good idea to add lots of organic matter as a mulch after digging in the gypsum, or to grow and dig in a green manure crop.

Unless you have a very large area the leopard and fig tree are not a good idea as they will be too big. Fig trees can cause lots of damage in a suburban yard - as their roots can destroy pipes, concrete etc. You can try some ferns and smaller palms as well as some native fuscia or tropical rhododendrons. The lillypillies should be okay there. Keep getting rid of the ochna.

If you are still unsure pop in to your local nursery and ask them for some advice.
(24/01/2001)

Q: I have bought some Thai Eggplant. The fruit are growing well but remain white. I have been waiting for them to turn purple as per the nursery tag drawing but some have started to yellow. Are they ripe (never having had eggplant before I wouldn't know) or is this because of the summer sun and I am impatient. The fruit are larger than a baseball.

A: Eggplant does take some time to develop - so perhaps you should wait a little longer - they take around 3 months to be ready. If they reach that age and are still not colouring as per the picture - sample one and see what it tastes like. Remember there are some basic rules to growing vegetables such as,

Good drainage and good soil structure.
Make sure the plants get enough sun - at least 4-5 hours per day. Most vegies love the sun.
The best position is one that has sun most of the day, is sheltered and is close to a source of water.
Regular incorporation of old organic matter ( such as compost ) will keep the soil working well.
Vegetables need nutrients more than other plants. Mineral fertilisers are reliable sources of good quantities of nutrients. Organic fertilisers are excellent for improving soil but their nutrient levels can be unreliable, they can be high in nitrogen. Additional dressings of Sulphate of Potash and Superphosphate may be necessary for fruiting crops. Get your soil tested for it's pH level, which is the level of acidity or alkalinity in the soil. Most vegies produce best results if grown at a soil pH level of between 6 to 7.
Mulching - preferably with an organic mulch which will help to retain moisture, suppress weeds, cut down temperature fluctuations and prevent soil crusting.
Avoid planting the same crops in the same spots, this is called crop rotation and helps prevent soil diseases.

(02/01/2001)

Q: We have rosella plants which are just starting to bear fruit but the leaves are getting eaten with green grubs. What is a safe insecticide to use on them?

A: One way to deal with the green grubs is to just be vigilant - each day, morning and night or just every time you pass the plants give them a quick once over for the grubs - any you find throw them on the ground ( give them a squash if you like ) and leave it to the ants to finish them off.

Two insecticides that are available from your local nursery are pyrethrum and natra-soap. Natra-soap is supposed to be biodegradable and after 2 days is gone.

You can also consider some home made remedies like these,

Contact Spray - you will need 4 large onions, 2 garlic cloves, 4 chillies and a handful of soap flakes - chop the vegetables, sprinkle on the soap flakes, mix with water and leave to soak for 24 hours. When strained the resultant liquid can be stored in a well sealed jar - for use, mix the concentrate with 5 litres of water and simply spray on.
Flour Dusting - another remedy you may like to try is flour - a good dusting will often poison caterpillars and the like.

Fruit trees and plats generally prefer full sun and good well drained soil. Fertilise regularly and keep up the water when fruit is growing. A layer of organic mulch over roots will help keep them moist, but don't allow to contact the trunk directly

Potassium is the plant nutrient that improves a plant's disease resistance. Apply regularly to build up your plants strength.
(02/01/2001)

Q: I have been regularly plagued by neighbourhood cats constantly fouling gardens and destroying plats/seedlings. Most of the repellents I have used to date have had only partial success. Can you suggest a deterrent which is likely to be more effective as a long term measure?

A: Cats can be a problem in the garden and getting rid of them is not so easy. There are several things you can do to try and make them as less of a nuisance as possible.

There are some plants that cats avoid, such as Geraniums, Petunias, Marigolds and Fuchsias and the herb dog bane but are attracted to Thyme, Catnip, Grand Ivy and Evening Primrose. Planting some of the plants that they dislike is obviously an option but you could also consider planting the types that they like in one area so that they will only affect that area.

You can also try so home made deterrents like these -

pepper - make your own with black pepper and chilli pepper - grind your own if possible because the smell will be much stronger - spread the powder on annuals and perennials to keep pets away
citrus - cats don't like citrus smells - scatter some orange or lemon peels to create no go zones - Citronella oil is considered to be good cat repellent but generally it does not appear to have any effect on dogs
mothballs - these contain naphthalene which repel animals - they can be used as a barrier around flower beds, but take care with children about
ammonia - dogs and cats absolutely detest the smell of ammonia - buy some cloudy ammonia and dilute with 10 parts water - spray around the garden and yard but always do a small test before applying to the plants

There are also some commercial deterrents available such as Scat and Keepoff - just follow the instructions on the labels - with keepoff it contains a strong perfume which interferes with the animals sense of smell.

Try to not use fish emulsion fertilisers as these can attract cats to the garden. From personal experience - when you put cane mulch around the garden it seems to keep them away ( possibly because they can't get to the soil beneath as easily)

It is hard to say that one method will keep them away forever - you will have to keep up your efforts for some time.
(28/11/2000)