WORK IN THE HOME GARDEN IN APRIL

New Zealand Journal of Agriculture, Volume 94, Issue 3, 15 March 1957, Page 241

WORK IN THE HOME GARDEN IN APRIL

FOR most home gardeners April marks the end of the main growing season. Cooler temperatures are the main factor in the decline in plant vigour and growth and because of reduced evaporation or drying out and greater condensation vegetation and generally soil remain moister than in summer; fungous diseases and rotting therefore become more widespread. Usually very little sowing should be done in April. In this article A. G. Kennedy. Horticultural Instructor, Department of Agriculture, Dunedin, discusses some work in the vegetable garden in April.

HTHE season of good growth for THE season half-hardy growth for tender and half-hardy crops such as marrows, pumpkins, cucumbers, and as marrows, pump Kins, cucumocis, aiiu tomatoes is finished, though steady growth can be expected from hardy plants such as those of the cabbage family, leeks, silver beet, and spinach. The harvesting and storing of crops such as onions, kumaras, pumpkins, marrows, and squash should be completed before low temperature or frost damage occurs. Low temperatures should be avoided for kumaras if they are to be stored, and frost is likely to damage and affect the keeping qua ity of plants such as pumpkins, marrows, squasn, ana even onions. Asparagus top growth should be cut when the foliage begins to turn yellow, because while the tops are green the plants are building reserves of food in the crowns which will assist

in the development of strong spear m the development of strong spear growth for cutting next spring. If cutting is deferred too long, seed may , . „ , ~ vonn « slants ome UD the following season become established to the detri.f, d . Ui u ' . Fern growth can be cut with hedge shears which have notched blades or with a sharp knife, and the bed can be weeded afterward if necessary. Top growth is sometimes left to dry and is then burnt on the bed but it is better to put it on the compost heap. Few kinds o vegetables should be sown in tbe open during April, even - n avoura bi e districts, though hardy, quick-maturing vegetables like spinach and turnips can be sown in most favourably situated, well-drained soils that are not too cold. Cabbages, cauliflowers, silver beet, and lettuces can

be set out in most districts, but seed should be sown only if t, e SOljs we drained and fertile and the aspect a situation are ravouraoie. Where winters are mild enough or autumn-sown carrots to \ succeed, a sowing of carrots should be made preferably early in the month. Seed should be sown as advised in last month>s “j ourna i”. blanched as Pplprv + oo should be blanched as , Ce ,5 y , . 0 sh ° mO n+h’s home eardescribed m last months home garden notes and leeks should be earthed up as they develop if long blanched stems are wanted. In some districts a sowing of peas can be made toward the end of the mon th in well-drained soil and in mos districts broad beans can be sown , preferably toward the end o f the month, though they are usually best sown in May. Ground should be cleared and du g over as each crop . g finished and refuse put on the compost heap or dug in. If the ground is not wanted for several months, a green crop should be sown. Seed of crops such as lupins or mustard can be sown where ternperatures are not too low. Elsewhere crops such as oats or barley can be sown.

Spring Cabbage If early spring cabbage is desired, sturdy, well-grown plants with good root systems can be set out in April, though in most districts planting can be extended over a considerable period from early autumn until mid-winter or even late winter, depending on climate and variety. April is, however, the favoured month in most districts, because if good plants are set out, they usually overwinter well and mature in spring, early or late according to growing conditions.

If they are set out too early, plants may make soft growth and if winter conditions are severe, they may be damaged and their growth checked. If set out very late, they may be late in maturing or if temperatures are low and conditions severe, the crop may fail because of disease or premature seed development. Cabbages planted late in autumn in exposed situations may not mature earlier and may be less satisfactory than plants set out in late winter or early spring.

The soil for spring cabbage should be rich in organic matter and in most home garden soils a dressing of organic manure such as farmyard manure, stable manure, or compost or a moderate dressing of fowl manure is likely to give best results. If the soil has not been limed recently and there is a risk of its being acid, a dressing of 3oz. to 4oz. of carbonate of lime per square yard is advisable. Heavier dressings may be necessary on some soils in high-rainfall districts.

As the effectiveness of lime is in direct relation to the closeness of its contact to the soil particles, it is best applied some time before planting. Distribution and incorporation by forking over should be as even as possible. Thoroughness of distribution is important, because there is little or no sideways spread of lime in the soil after it is applied, though its downward spread is assured by the leaching action of rain-water.

Though the manurial needs of cabbages are heavy, care should be taken to distribute fertilisers or manures evenly, as young plants may be checked if the roots come in contact with too heavy concentrations of manure, particularly at a time when low temperatures limit growth. Where organic manures are not available a green crop should be dug in and except where the soil is very rich the organic manure or green crop should be supplemented by a complete fertiliser at about 2oz. to soz. per square yard.

In addition side dressings of nitrogenous manures such as nitrate of soda or sulphate of ammonia are often advisable, particularly where organic matter applied to the soil is strawy rather than sappy and well rotted and

when quick, forced growth is required (as when temperatures rise in early spring).

Spring Cauliflower The requirements of cauliflowers are similar to those of cabbage except that cauliflowers are more sensitive to adverse conditions such as extremes of heat and cold, wetness and dryness, or cold winds, and if checked, they are likely to “button”; that is, form only useless miniature heads. Frosts, too, will damage the curds, and the injury so caused is likely to permit the entry of soft-rotting organisms. Cauliflowers should therefore be planted out only in districts or situations where winters are not too severe. In unfavourable situations planting is best deferred until late July, August, or even September. Good hardy varieties of cauliflower suitable for planting now are Walcheren, All Seasons (All Year Round), and Early London Cauliflower plants are obtainable from most seedsmen.

Sweet Potatoes or Kumaras Home gardeners who grow sweet potatoes usually leave the main crop to develop as long as possible, because sweet potatoes gain rapidly in total

yield and the table quality of mature tubers is better than that of immature ones, but where tubers are to be stored, digging should be completed before there is risk of low temperature injury. Even if it is not intended to store tubers and an unusually early frost kills the tops, it is advisable to remove them promptly, as rots develop in the foliage and sometimes penetrate to the tubers. When sweet potatoes are mature enough for storage the skins should be reasonably firm. They can be tested by cutting; when they are cut mature tubers dry rapidly and cleanly on exposure to the air. Most varieties of sweet potatoes are likely to be injured when the temperature falls to 40 degrees F. (8 degrees above freezing point) and the keeping quality is so seriously affected that long storage is usually impossible. For best results the tubers should not be subjected to temperatures below 50 degrees F. If sweet potatoes are carefully harvested and properly cured and stored, it should be possible to keep them until next season’s crop is ready, but if digging is delayed until after frosts and tubers are left for several days in wet,

cold soil, loss during storage may ultimately be very high. Even a few days at 40 degrees F. may cause discoloration, and if the tubers are set to grow shoots for cuttings, poor sprouting is likely to result.

To ensure that their quality remains at its best from one harvest to another tubers should be handled with care. Badly damaged ones should be rejected and the remainder subjected to a period of fairly high temperature and humidity to cure them and enable wounds to heal. They should then be stored in most hygienic conditions at a temperature of not less than 50 degrees F.

Where small quantities are being stored a reasonably warm shed or cellar is usually suitable if the tubers are placed in dry sawdust or dry sand. Deep placement in dry sand will prevent rats from getting to them.

Where large quantities are stored a pit or bank similar to that used for potatoes is occasionally used, though it is not generally recommended. However, a pit may be satisfactory if it is well made and insulated against cold and wet and if there is room for a person to move about in it. It should be clean and vermin-proof, as rats and

mice not only eat the tubers but spread diseases that cause rotting.

Lined storage places, bins, and containers that are used year after year should be sprayed with a suitable fungicide before being used. Copper sulphate (Jib. to about 12 gallons of water) makes a suitable spray.

Curing of Tubers

Proper curing is as necessary as care in lifting and handling. In New Zealand curing of a kind is usually done by gathering the tubers into heaps and leaving them for about a week and keeping them covered during rain or at night with their vines or old sacks. Where temperatures are sufficiently high quite fair results are usually obtained from this method. By the time the tubers are ready for storage damaged ones which may have been overlooked have begun to decay and can be rejected.

If tubers are to be properly cured in the field, they should be subjected to temperatures of not less than 70 degrees F. and fairly high relative humidity day and night for as long as 3 to 4 weeks or more. Such long curing is not usually a practical proposition in New Zealand, however, because of the need to grow the plants for as long as possible. Curing for too long may result in excessive sprouting.

It is rarely possible for the home gardener to cure his sweet potatoes under ideal conditions. It is difficult even for the commercial grower unless large quantities are grown and stored, as a strict routine must be followed.

Onions

Harvesting and curing of onions for long keeping should be completed as soon as possible, as the weather after April becomes progressively less favourable for drying bulbs and proper drying and curing are essential for long keeping. Only sound, wellformed bulbs which have been properly cured should go into long storage; others should be put aside for immediate use. Small quantities can be strung or stored in open mesh bags in a cool ventilated shed or cellar, but because of the injury which often results when there is a heavy weight of onions in a bag, it is advisable when storing considerable quantities of onions to use specially made slatted storage crates or to store them on slatted shelves.

Onions should not be exposed to direct sunlight during storage, as it may promote early growth; nor should they be exposed to excessively moist conditions, as it may encourage the development of roots, which are exhausting to the bulbs. If it is necessary to store them outside, a dry, sunless position, where there is good air draught is desirable. In favourable sunny situations the onions can be hung on a frame as illustrated in last month’s notes, but they should be covered against rain, and air should circulate freely around them.

When onion plants ripen properly the leaves weaken in the neck or region just above the bulb and the top falls over and the leaves remain green. If the top dries from the tips toward the base while the plant stands erect, the neck is not closed and the bulbs may not keep well in storage.

Unfortunately onions in a crop rarely mature uniformly and the best time to begin to harvest them is when about 20 to 25 per cent, of the tops have broken over. If onions are completely ripe when they are harvested they tend to root rather easily if left lying on moist ground and this sort of growth is difficult to check and usually makes them unfit for anything but immediate use. If onions are pulled when they are slightly immature, they tend to retain their outer skins better and are less likely to sprout and root than if they are cured in the field.

Immature onions are, however, often less solid than fully mature onions and the stage at which onions are harvested must usually be largely governed by climatic conditions, drying and storage facilities, and whether they are for long keeping or more immediate use.

Not all onion varieties are suitable for storing. In New Zealand the most generally preferred variety is Pukekohe Long Keeper.

Autumn-sown Onions

Though autumn sowing of main crop onions is a fairly general practice in

the North Island, it is rarely done in southern districts. In most districts late March or early April is considered the best time for autumn sowing. In southern districts the onions are not usually thinned, but are kept cultivated and grown on until about November or December, when they are used as “thick necks” without being encouraged to form large bulbs. In most northern districts, however, the plants are lifted in early spring and set out in rows 12in. to 15in. apart, with the plants 4in. to 6in. apart in the rows. Autumn sowing in some districts is rather risky, and where winters are severe success depends to some extent on the season. Early frost will sometimes “lift” and damage late-sown crops, whereas if the seed is sown too early or if a long period of mild weather precedes a very severe cold period, the plants sometimes run to seed before they have developed adequately. Though this is true of autumn sowing in general, in the north, where winters are less severe and mildew is more troublesome on the later crops,

the risks are much less and autumn sowing and transplanting of the main crop in July or August are quite common. For autumn sowing the ground should be deeply cultivated and broken down to a fine tilth. It should be gently firmed, but care should be taken where the soil is heavy to avoid firming it too much, as the heavier soils tend to consolidate excessively where they are subjected to frequent winter rains. If well-rotted stable or farmyard manure is available, it should be incorporated some time before the final preparation of the soil is begun. Best use can be made of such manure by adding it to land on which the crop is to mature. If keeping quality onions are required, it is not advisable to apply excessive quantities of organic manure in spring, as the bulbs may be stimulated into excessive leaf growth and weed growth is likely to be more troublesome. Few home gardeners are likely to have much farmyard manure, and available organic matter such as compost plus a complete fertiliser applied at the rate of about 3oz. to 6oz. per

square yard should be used. Because of the great variation in soils and their condition throughout New Zealand only local experience and knowledge can indicate fertiliser requirements, but if soil conditions and fertiliser placement are correct, it seems unlikely, judging by experiments that have been carried out, that onions will be over-fertilised. In general a fertiliser high in phosphoric acid but containing a liberal amount of potash and a smaller amount of slowly available nitrogen will give excellent results. The phosphoric acid

and most of the nitrogen for early planted crops can be supplied conveniently by finely ground bone meal and the potash can be supplied by muriate or sulphate of potash. The practice of growing onions on the same land for several years in succession has not much to commend it. It probably arose from a recognition of the high fertiliser needs of the onion and consequently the desirability of maintaining an area of the garden in very high fertility and regarding it as the onion bed. However, rotation is just as important in growing onions as in growing other crops, as diseases to which the crop is especially subject tend to build up in soil unless crops are rotated. In addi-

tion most other vegetables grow well without further fertiliser on land that has received the heavy fertiliser applications usually given to onions. Onion seed should be sown Jin. deep at the rate of 10 to 20 seed per running foot in rows 12in. apart in finely cultivated soil. The growth of onions, unlike that of most other crops, is not usually seriously affected by moderate crowding in the rows, and provided the seed is not sown too thickly, thinning should not be necessary on most soils. Good varieties of onions include Ailsa Craig, Straw Spanish (early), and Pukekohe Long Keeper (main crop or long keeping).