Gardeners’ queries

Press, 30 September 1983, Page 14

Gardeners’ queries

GARDENING

by

M.Lusty

I am worried about a plant called the asparagus fern which I have in the house. I took it outside when it rained and soon the container in which the plant stands was covered in thousands of tiny white jumpy things. Nobody seems to know what they are. The soil came from the vegetable garden. There does not seem to be anything on the foliage. I would be very grateful for advice about these creatures. R.M. (Reefton). It is quite probable that the insects observed were collembola, commonly called springtails. When disturbed they use a folded appendage under the body to leap about, hence their common name. These insects prefer damp, warm situations and feed on above-the-ground portions of plants; they may be particularly damaging to seedlings. It is doubtful whether they would do much harm to your asparagus fern, particularly in the short time that it would be exposed to their attentions — a good shake before bringing it in should rid the plant of them.

Could you advise what is wrong with my camellias. Both were bought just over 12 months ago. The sasanqua is in

a different position to the larger leafed one but both seem to have blotches of brown on the leaves. Both have had acid food and also horse manure. The sasanqua is not losing its leaves but the other one is. S.L. (Chertsey). The appearance of the leaves suggests that the problem is cultural rather than physical. The best way to track down the cause is to examine various aspects which could be at fault, including planting depth, over feeding, and possibly position.

Just now all the carrots in the garden look like they are going off. I’ve enclosed some leaves so that you can see what I mean, and they are nearly all the same. We’ve

done nothing to them at any time and wonder whether it’s too late to save them now. Also, the silver beet is getting all tatty — could it be slugs, or is it a disease? M.S. (Chch). The discolouration of the foliage of the carrots is due to an infestation of aphids. These pests can be responsible for a virus infection called motley dwarf and the almost complete dying off the leaves. Maldison, acephate, or permethrin will give good control. Regarding the silver beet, it is not at all uncommon for various leaf crops such as silver beet to be ravaged at this time of the year by birds, although slugs and snails can be a problem as far as seedlings and newly planted vegetables are concerned.

Could you please let me know what is wrong with this passion fruit? I have two healthy vines but all the fruit is going like the enclosed. R.S. (Tai Tapu). Indications are that these passion fruits have suffered from the past winter weather. The fruit is regarded as subtropical and, as such, low temperatures can affect the quality of the fruit. The best situation for a passion vine is

sheltered, sunny’position which is protected from more than light frosts. Good drainage and good soil are also desirable for best results.

I’ve enclosed a couple of carrots with a parasite attached to them. When I first saw these plants they were growing among my blackcurrants but I’ve dug them out and put the rotary hoe through them. I guess that spread the parasites over the garden. 1 would be grateful if you would identify the problem. F.F. (Chch). The samples of carrot provide a very good example of parasitism in plants. In this case the parasite is broom rape, which is supporting itself by drawing on the food reserves of the carrot. Some of these parasites can survive only in the presence of specific hosts and the seed which is produced will germinate fully only when it comes into contact with a suitable host. Soil sterilisation would probably provide the best means of achieving control although it may not be entirely successful without a follow-up. It is suggested that dazomet be used according to the manufacturer’s recommendations.