FAQ's
See what advice is given to other gardeners on specific garden topics. Or ask your own question (contact page) - we will reply with a solution as soon as we can.
Bulbs
Q. What do I do with my bulbs after they finish flowering?
A. Trim off dead flower stems and, if you want to keep the bulbs for next year, water them regularly with a liquid fertiliser (like Thrive or Nitrosol) until the leaves die down completely. Then lift the bulbs, clean them and store them somewhere cool and dry. Cool climate bulbs – like tulips, hyacinths and daffodils – should be placed in the crisper section of the fridge in February and left for at least two months before being planted out. Re-using bulbs can be a chancy business, especially if your winters are not particularly cold, and if you want best results you should buy fresh bulbs each year.
Fertilising
Q. Why hasn’t my plant flowered? It has lots of beautiful leaves and looks very healthy?
A. The soil may contain too much nitrogen relative to the other nutrients. Apply Thrive Flower and Fruit or Sulphate of Potash.
Q. When I spread dry fertiliser around my garden the plants ended up all turning brown on the edges. Why?
A. Dry fertilisers contain a high proportion of soluble nitrogen that will take water from the nearest plant if there is insufficient moisture in the soil. Always water dry fertiliser in well immediately after application.
Q. Why is it best not to fertilise in winter?
A. Most plants grow predominantly during the warmer months of the year. This is when they require both moisture and nutrients for growth. During winter, when there is no or minimal plant growth, plants require little or no nutrients, therefore it is unnecessary and also wasteful to fertiliser in winter.
Q. What is the dilution rate of hose-on products?
A. Hose-on applicators dilute at approximately 30:1. (water to product). Therefore Weed’n’Feed hose on can be used @ 300ml per 9L water and applied over 20 m2 with a watering can and sprinkle bar.
Q. Are the heavy metals in Fertilisers dangerous?
A. Many of the nutrients in mineral fertilisers are originally derived from natural mined sources. These contain a small background level of heavy metals, just like garden soil. It’s important to note, however, that common foods also contain heavy metals. For example chocolate contains cadmium and seafood contains mercury. These foods will most likely provide more heavy metals in the diet than home garden fertilisers.
Fruit
Q. The new leaves on my peach tree are all curled and bubbled and some of them are falling off. Why?
A. This is caused by a fungal disease called leaf curl. The tree must be sprayed with Champ DP at bud swell (when new buds show tips of colour). By the time the leaves show the damage it’s too late to spray.
Lawns
Q. I’ve sprayed my lawn with Weed ‘n’ Feed but I wondered how long I’d have to wait before I can let my dogs on to the lawn?
A. As soon as the grass is dry the dogs can be allowed onto the lawn. Discourage them from eating any of the grass during the first week and then mow. Don’t use clippings as mulch unless composted for at least 6 months.
Q. I can’t spray my Weed ‘n’ Feed close to the garden beds. How do I break it down to use in an ordinary spray container?
A. Mix the chemical with water at a rate of 30:1 (thirty parts of water to one part of chemical). 300 mls in 9 litres of water over 20sq m. This can then be applied using a sprayer or a watering can and sprinkle bar.
Q. What sort of lawn can I grow in the shade of a big tree?
A. Possibly no lawn at all. Grasses love sun and do best in as much sun as possible. Cool season grasses tend to have more shade tolerance but, obviously, are more suited to cooler climates. If grass always fades away in a particular part of the lawn, then it would be best to switch to paving or shade tolerant ground covers. Could also try growing Lush Sun’n’Shade grass seed if enough light is available under the tree.
Q. Is winter a good time to sow lawn seed in colder areas?
A. No, lawn seed does not germinate well in cold soil.
Pests
Q. The leaves on my azalea look dull and grey with dark spots underneath. I’ve watered the plants well but the leaves haven’t improved. Someone told me it’s probably red spider. Would this be right?
A. It’s likely to be caused by thrips, tiny sucking insects that shelter beneath the leaves and cause the classic discolouration and spotting you have noticed. They are active during warm weather. Spray with Baythroid or Confidor. Confidor’s systemic action will give good control without contacting the insect directly.
Q. What is the best time to spray for scale?
A. Scale can be treated at almost any time of the year, but it’s best to spray during the warmer months of the year when scale pests are most active.
Q. Is it ok to mix different garden chemicals together?
A. Unless the label specifies that a product can be mixed with another product, it’s best not to mix chemicals together. Instead, spray one product, wait for several days and then spray the other product. Check individual product labels for any special precautions.
Pot Plants
Q. How should I care for plants in pots?
A. Use a quality potting mix. Soil in pots form what is termed a ‘perched water table’, which holds excess moisture within the root system. Potting mix gives guaranteed drainage. Never allow the base of a pot to sit in water. Plants in containers should always be regularly fed with a controlled release fertiliser such as Nutricote because potting mix, as it decomposes, uses up nitrogen within the mix.
Q. How do I work with potting mix safely?
A. Potting mixes, just like garden soil, may contain micro-organisms that can cause respiratory illnesses. It’s important to follow all the safety directions on the label, which may include wearing a dust mask, gloves, and to always wash your hands after handling potting mix or garden soil.
Roses
Q. How do I control black spot on my roses?
A. Spray the foliage regularly with Baycor, Shield, Supershield or Rose Gun Ready To Use. Water the plants in the morning rather than in the evening. Always water at the base of the plant, rather than on the leaves. In winter, spray the leafless plant with lime sulphur immediately after pruning. Grow rose plants in an airy position in full sun. Choose vigorous varieties. Regular feeding, manuring and mulching will help plants to resist disease.
Seeds
Q. What does it mean when the seed packet has stamped on it “Caution treated with Thiram. Do not use for food, feed or oil”?
A. This means that the seeds in this particular pack should not be eaten because they have been coated with a thin slurry of fungicide. The fungicide breaks down rapidly in the soil and does not have any effect on the resulting plant. Although slightly ambiguous in wording, this form of wording is accepted by all the relevant MAF and Custom authorities.
Q. Why do my seeds germinate and then make no more growth?
A. Seedlings make their initial growth from the energy contained within the seed itself. After that stored energy is used up, the seedling must begin to make its own food. In order for the seedling to function it needs to have access to plant nutrients. Young seedlings can be regularly watered with a fertiliser such as Black Magic Seedling Fertiliser. Thrive Soluble All Purpose or Nitrosol Original can be used at half strength.
Q. Why are my seedlings leggy and too tall?
A. This is usually an indication of too little light. Move seedlings into a position with better light, or outside if they are indoors. Thin out the seedlings if they are crowded.
Q. I sowed some bean seeds. Why didn’t they come up?
A. Beans need warm temperatures for good germination. Don’t be tempted to plant them too early. The seeds are capable of absorbing quite a lot of water and can rot away readily, so keep watering to a minimum. Handle bean seeds gently: the seeds are surprisingly fragile and the growing point is easily damaged.
Q. Why is my sweet corn not germinating?
A. Sweet corn requires warm soil for germination (above 13°C for standard sweet corn varieties and about 18°C for super sweet varieties). This means air temperature is several degrees warmer. Too much water will also cause the seed to rot.
Q. Why are my Sweet Peas not flowering?
A. Sweet peas need to grow in a full sun position. Addition of too much Nitrogen based fertiliser encourages leaf growth but not flowers. Some sweet peas are ‘long-day’ varieties that don’t flower until later in spring.
Q. Why aren’t my seeds germinating?
A. Over-watering is the main cause of seed failure for most types of seeds. Seeds need water and oxygen to germinate, so are best started in a light, loose soil that will not compact, get soggy, or crust over. Free flow of water & air are a must. Cover seed with 2 – 4 times their thickness of soil, unless they require light to germinate. Barely cover small seed, and sprinkle fine seed on the surface and water by misting. Lightly tap soil to insure good contact with the seed, unless heavy. Keep soil moist, not soggy, and do not allow to dry out. Common causes of failure are soil too heavy, wet or cold, or allowed to dry out, not giving slow seeds long enough to come up, pests eating the seeds or seedlings, and not giving dormant seeds the proper pre-treatment. Careful attention to the instructions and on the packet will help ensure good results.
Q. Which seeds need darkness to germinate?
A. Calendula, Delphinium, Gazania, Pansy, Phacelia, Phlox, Salpiglossis, Sweet Pea, Vinca, Viola, Coriander, Parsley.
Q. Why are my dwarf beans climbing?
A. Continuous dull cloudy weather or growing in less than full sun can cause this problem. Cut off the long shoots and the plants will stop climbing when the sun comes out again. This is also due to extremely warm temperatures and the heat causes the plants to produce tendrils, or become taller than usual.
Q. Why are my Curcurbits not fruiting?
A. Poor fruit production in these crops is commonly a result of inadequate pollination. Cucurbit flowers only remain open for one day. If pollination does not occur, the flowers simply drop off the plant & no fruit is produced. Female flowers have a swelling at the base which may look like a small fruit. This will wither if not pollinated. If only partial pollination occurs, the resulting fruits are small and not on the vine. Some cucurbits require as many as twenty bee visits per flower for pollination. Many cucurbits, especially newer varieties, produce far more male flowers than female flowers. Male flowers appear first on the vine and will never produce fruit but are needed to pollinate the 2nd flower, usually female. If this doesn’t occur, or if temperatures are too high, only male flowers will appear as the vine grows. Some cucurbits produce male flowers and combination flowers, in which case only the combination flowers will produce fruit. Insect vectors, however, are still required for pollen transfer even though combination flowers have both male and female reproductive parts. Regular feeding and watering are needed for the young plants or the flowering pattern is disrupted for the life of the vine.
Weeds
Q. How long does it take for Roundup or other glyphosate products to kill weeds?
A. It depends. Roundup has to translocate through the plant’s system and travel down to the roots. The process of translocation takes more or less time, depending on the current growing conditions. A plant can die within a week, or it can take several weeks if conditions are cold, dry, or very hot.
Q. Why doesn’t Roundup seem to work in winter
A. Glyphosate in Roundup relies on the weed growing actively, so that the herbicide moves from the leaves to the roots. In winter, there is minimal weed growth, which means little or no movement of the glyphosate to where it does its work.
