Weeds, diseases and pests
Weeds are an irritation, but some thought and care can help to minimise their nuisance.
Index:
What can I do to stop weeds
Weeds are almost impossible to eradicate once they are growing through the roots of perennials, so target them early on.
1. Before creating the border try to eradicate the perennial weeds - roots and all - as far as you can. Thorough digging is the answer here.
2. After this, carefully remove annual weeds throughout the growing season. Do not hoe between perennials, as this can easily damage the roots of the plants.
3. Spread a layer of 3 to 5 cm of organic mulch on the soil between the plants to prevent weed seeds from germinating. Pre-packaged potting soil and compost are ideal for use as mulch and are guaranteed sterile.
Ground elder, bindweed and horsetail are some of the most stubborn weeds, because each piece of root can grow into a complete plant again. By consistently and continuously hoeing everything that raises its head, you can ultimately eradicate them. You should regularly rake through gravel and chippings in order to disrupt weed growth.
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Moss in the lawn
Moss can be caused by:
a. Shade;
b. a section that is too damp;
c. if there is too little air in the soil and the grass is cut too short.
In these situations the grass struggles and will take a long time to recover. Moss grows much more quickly. Moss can be suppressed by generous feeding, amongst other things. The grass then grows so fast that the moss cannot compete. Lawns which suffer heavy traffic can be aerated by pricking holes in them with a garden fork. Brushing sharp sand into the holes keeps them functioning for longer.
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Diseases
The old adage that prevention is better than cure definitely rings true here. You can do a lot to prevent diseases in your plants. Plants which are happy are unlikely to sicken very quickly. Ensure good growing conditions for your plants, or better still: go for the right plant in the right place - choose the plants which match the conditions in your garden.
If, following your best efforts, plants nevertheless show signs of disease, it is best to obtain expert advice straightaway. Do this at your garden centre, through gardening magazines and clubs, gardening pages in newspapers or radio phone-ins. Consult books and the internet too
Here are a few pointers to help you get started if disease problems arise:
1. Roses
With roses be particularly alert for black spot and mildew and combat these fungi as soon as they appear.
2. Clematis
Large-flowered Clematis in particular can suffer from wilt, a nasty disease which causes the shoots to die. Luckily they only do this above ground. Anything below ground remains healthy. This is why a Clematis is always planted a bit deeper than it is in the pot in which it was grown. If the disease strikes, it can regrow healthily out of the ground. Make sure you cut the diseased shoots back to ground level.
3. Fruit
Fire blight is one of the most destructive disease in fruit trees. Pears are particularly prone to it. Sure signs of the disease are wilted, blackening twig ends. Dark-coloured, slightly sunken patches also appear on the trunk. Slime can sometimes ooze from the stems of wilted flowers (particularly during follow-on flowering in the summer) and leaves.
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Apples can be prone scab and mildew
Silver leaf is the most common disease affecting plums. The upper surface of the leaf is loosened by this disease, allowing air to get underneath it. This gives it an unusual silver or lead-like discolouration of the leaf. It is an aggravating disease which can in time kill a tree. Gum formation can also be a problem in plums.
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Botrytis
Botrytis can attack flowers, leaves and fruit remarkably quickly. Combat this fungus with a suitable fungicide as soon as you spot it anywhere.
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Beneficial animals and pests
All sorts of insects are active in a healthy garden - and that’s the way it’s supposed to be. Generally there is a natural balance in which they keep one another in check and do little harm. It only becomes a problem if one species suddenly dominates.
If serious damage is then caused to the plants, it is best to take steps. But don’t overdo it. In many cases nature will restore the balance itself.
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Useful animals in the garden
Just as there are beneficial insect predators, birds and mammals can also help you maintain a healthy balance in the garden. Tits (including great and blue tits) eat pests including caterpillars. And plenty of them! If they have a nest with chicks, then hundreds will vanish down the hungry throats.
Tit nesting boxes will encourage the parent birds to nest, particularly if you have many different plants in your garden. Ladybirds eat aphids, as do earwigs. Hedgehogs also eat large quantities of insects, slugs and snails?
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Pests
1. Slugs
There are all sorts of ‘home remedies’ for combating slugs. Slugs are mainly nocturnal. You can catch them by hand during their night-time feeding expeditions. One of the best remedies are the environmentally-friendly slug pellets which are not hazardous to birds or pets.
The pellets mean that there is no clearing up to do, since the slugs retreat underground to die. Some people also swear by beer traps, and spreading sharp sand around the base of vulnerable plants works too.
2. Aphids
Aphids can be very troublesome but only tackle them if they are a real plague. The healthier your plants are, the less they will be affected. A black mould (black spot) can develop on the sweet fluid (honeydew) excreted by aphids.
You will then need to use both a product against aphids and a product against fungi. Never apply insecticides during the day. Bees are very active then and they will suffer. If you have to use an insecticide, wait until the bees have retired for the night.
3. Earwigs
Earwigs can be a particular problem on dahlias and chrysanthemums. Their nibbling can cause considerable damage to the flowers. You can catch them in a special earwig pot which you fill with hay or straw (wood shavings or some screwed-up paper will work as well) and place upside-down on a cane by the plants.
It is harder to do with an ordinary flower pot because it tapers, which means that the contents are more likely to fall out. The earwigs are active at night and hide during the day. You can then remove them easily.
4. Algae
Any pond will develop algae at some time. Algae spores float everywhere in the air and when they come into contact with water, algae can grow. There are various types of algae. Everyone is familiar with the floating algae which can transform a pond into a green soup in early spring. This is usually short-lived and ends as soon as the water plants start taking nutrients out of the water.
If you are still suffering from floating algae later in the year, then the pond water contains far too many nutrients. That can be caused by having too many fish. Another very well-known type of algae is filament algae which form large wispy masses of greenish-white threads. Fish like to lay their eggs in it and eat it. Filament algae also brings oxygen into the water thereby improving water quality. However, it is still best to remove excess filament algae.
Erect algae have a structure which is reminiscent of ordinary plants, so with stem-like and leaf-like elements. Algae are unicellular plants - some types can form thread-like masses but usually they float loose in the water.
Unlike fungi (moulds), algae have the chlorophyll needed to create food from substances absorbed from the surroundings (the water). They do not have any roots, so they cannot extract nutrients from the soil.
Some of the erect types of algae that you might encounter in a pond are Enteromorpha intestinalis which forms tubes rather like intestines, Chara fragilis which resembles horsetail, and the rare Batrachospermum moniliforme which forms strings of slimy indigo to green spheres. If the latter occurs in pond water, there is usually something wrong with the water quality.
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