The Home Garden in March

New Zealand Journal of Agriculture, Volume 96, Issue 2, 15 February 1958, Page 181

The Home Garden in March

By

A. G. KENNELLY,

Horticultural Instructor, Department of Agriculture, Dunedin

THERE is usually comparatively little sowing or planting to be done in the home garden in . March because the main winter crops, such as savoy cabbage, kale, broccoli or winter cauliflower, silver beet, leeks, and root crops, such as carrots, parsnips, and beetroot, are well established. Routine work includes weed control, the sowing or planting of a few crops to mature or to become established before winter, composting, watering, or giving liquid manure where necessary, and digging over and sowing vacant land with green crops.

EARLIER-SOWN crops, such as lettuce, spinach, and silver beet can be thinned, or seedlings can be planted out. Any crops infested with aphids should be sprayed with nicotine sulphate or lindane. If red spider mite is troublesome, it can be controlled by spraying with one of the certified miticides now on the market. Most relatively active creatures, such as caterpillars, green vegetable bugs, vegetable weevils and their larvae, can be controlled, by DDT dusts or sprays.

Celery should be 'sprayed against leaf spot. Where potato blight is likely to be troublesome, potatoes and tomatoes should be sprayed with a copper spray or other certified material.

Compost

The compost heap can be built up with garden rubbish. Care should be taken to burn crop refuse infested with insect pests or infected with disease. Certain fungi produce hard, black - resting bodies, known as sclerotia, which enable the fungous diseases to persist for long periods in the soil. It is important that these resting bodies should not be allowed to fall to the ground or to be included in a compost heap.

Onions and shallots should be harvested in March, if this work has not yet been done, and the properly cured bulbs stored in a dry, airy place. The pods of peas and beans should be gathered before they are fully mature

to encourage plants to continue bearing. Vegetables intended for winter and spring use, such as cauliflower, broccoli, kale, leeks, savoy cabbage, and silver beet, should be kept cultivated and, where necessary, fed with liquid manure or given side dressings of fertiliser to ensure that good growth is maintained. Celery should be blanched as it reaches maturity or just before. If the work is started early, sections of the crop can be blanched progressively, so that the heads will be in their best condition for a considerable period as they are needed. Toward the end of the month, in districts where winters are not too severe, a sowing can be made of carrots and onions for spring use. Spinach can still be sown for late autumn or winter use in most gardens, and cabbages, silver beet, and, in rea-

sonably favourable situations, cauliflowers can be set out. In specially favoured districts where soil conditions are good, particularly in the north, sowings can be made of crops such as beetroot, turnips, silver beet, and radishes. Carrots Carrots are one of the most important and popular vegetables because of their nutritional value, flavour, and long period of availability, but many home gardeners have difficulty in growing satisfactory crops from late spring and summer sowings. Apart from the need for a wellcultivated, highly fertile soil, one reason for lack of success is that seed does not germinate, nor do young seedlings grow well when soil conditions are very hot and dry. The roots of established plants stand fairly high

temperatures, possibly in part because they are in the relatively cooler undersoil, but growth is usually better when temperatures are not too high.

In districts where winter temperatures are not too low home gardeners desiring early spring carrots should make a sowing about the end of March. Where drainage is poor a raised bed is advisable and for convenience in cultivating and harvesting the bed should not be more than 3ft. wide. Soil heavily manured for the previous crop is best and sandy or light loams are especially suitable for autumn crops.

Soil Conditions

Soil should be of good texture and should not bake or form a crust after rain, or emergence and growth may be adversely affected. Heavy soils on which growth is comparatively slow tend to produce thick, short carrots with greater core development and poorer table quality than do lighter, more free-working soils.

. Trials. with some popular varieties, Chantenay for instance, have shown that roots which are accepted as most typical of the variety are produced when the temperature during growth is about 65 degrees F. At 10 degrees lower they are longer and thinner and at 10 degrees higher they are shorter and thicker.

Carrots vary in shape, colour, and size according to variety, but all these characteristics may be influenced by soil conditions. Soil influences size more than it does shape. Colour, too, varies considerably. The colour most desired by the housewife is usually red or orange-red and is a result of an accumulation of a substance called carotene.

Irregular moisture supply and high temperature bring about the development of a rough surface on the carrot. Horizontal depressions, which may be quite deep, occur on the root and

make it wasteful in preparation for the table.

Sowing

Carrot seed should be sown thinly Jin. to fin. deep, according to whether the soil is heavy or light, in rows about 12in. apart. If the soil is light and free, there should be no need to thin young plants, but on heavier soils they can be thinned to about 2in. apart. Thinning should be done preferably when the soil is moist so that the remaining seedlings are disturbed as little as possible. If thinning is delayed, the thinnings can be used for

soups and stews. An eighth to a quarter of an ounce of seed should sow about 100 ft. of row.

Carrot seedlings are delicate and cannot compete with weeds or withstand drying out which may result from baking or cracking of the soil. Cultivation should therefore begin as soon as the rows can be distinguished. A little radish seed, which germinates quickly, is sometimes sown with some of the carrot seed to give an early indication of the position of the carrot rows.

Good varieties include Chantenay, Taranaki Strong Top, Nantes, and Morse Bunching. Scarlet Horn is widely used where a quick-maturing carrot is wanted.

Celery

Early celery should now be ready for harvesting. As some of the quickmaturing varieties that are usually grown for early use tend to become overripe and pithy and lose weight and flavour if held too long, the plants should be watched for signs of near or full maturity and harvested and used then.

Celery is usually harvested by removing the blanching paper or boards and then driving a sharp spade or cutter under the bases of the plants to be removed. The plants can then be lifted, the remaining roots trimmed off with a sharp knife, and any damaged outer leaves stripped off.

The quality of celery,' like that of most. other vegetables, falls off progressively the longer it is kept after harvesting. Falling off in quality is less important if celery is to be. used in soups or stews than if it is to be used for salads. Good produce may be stored up to 2 to 3 weeks at cool to near freezing temperatures and though some of the inferior types of celery which are often grown for early use are best used (if for salads) immediately after harvesting, all varieties of

celery, whether early or late, can be stored in a refrigerator or in a trench if it is in a sufficiently cool, shady part of the garden.

Where celery is stored in a trench ventilation must be good or rots are likely to develop. The plants should be stood upright so that the bases, either partially or cleanly trimmed, rest in the cooler, moist soil at the bottom. The trench can be covered with two fairly wide planks set to form a ridge to turn rain and provide shade.

Though celery does not tolerate low temperatures in the early stages of its growthlow temperatures may cause premature seed stalk development—when past the seedling stage and well established it thrives if the weather is relatively cool.

Liquid Manure

As celery is a moisture-loving plant and as its fertiliser needs are high, liquid manure is usually helpful where conditions tend to be dry and soil fertility is low. Blanching of the main crop is usually begun in most home gardens in March, early or late in the month according to growth of the crop, variety, and district. Most selfblanching varieties can be blanched in from about 10 to 21 days, but with the non-self-blanching varieties blanching may take about 14 to 40 days, according to variety, temperature, the extent of blanching desired, and whether it is done in stages.

Self-blanching celery is usually blanched by placing 10in. or 12in. by lin. boards held in place by pegs round the sides of the beds. Stiffened paper can be used if desired in place of the boards.

The non-self-blanching type of celery can be blanched similarly, but as a much longer period is needed for blanching, plants are usually either wrapped individually in stout paper held with string or elastic bands or earthed up in fine weather with clean, free-working, reasonably dry soil. Preferably this should not contain much organic matter likely to cause rots and be free from the eggs of slugs or similar harmful creatures. Small or decaying outer stems should be removed before earthing up is done.

Earthing, up is the most difficult way of blanching. The earth when banked up should be ridged sharply and the soil surface beaten smooth with a spade to shed rain. Under wet conditions rots may develop if soil remains touching the inner stalks after earthing up; stems" should therefore be drawn together with the soil packed round them.

Blanching with clean, odourless paper is quite satisfactory. A long strip of strong paper can be placed along the sides of the bed and held in position with heavy, arched wires. Blanching tends to check growth and therefore should not be begun until the plants are well on toward maturity. If, however, a good head of leaves is

left at the top and soil is used for blanching and is not too tightly packed, plants should continue growing. Self-blanching varieties contain very little chlorophyll in their leaf stems and can be blanched very simply and quickly with paper or boards. Home gardeners who have a large planting of one variety’ of celery and who intend to harvest it over a long period can begin blanching when the plants are about two-thirds' grown. In the U.S.A, green celery has largely displaced white celery and many new varieties of excellent quality have been bred to suit particular conditions in that country. Celery Leaf Spot Celery leaf spot is the most serious disease of celery and often injures foliage severely and blemishes the outer leaf stalks. It may be ’ seed borne and often infection starts from the seed. Leaf spot may be caused by one-or other of two closely related fungi which give rise to somewhat different though superficially similar symptoms. , When fine, dry weather prevails after planting the spread of the

disease may be slow, but if a spell of wet weather intervenes or overhead irrigation is resorted to, the spread may be rapid. Damage is usually worse when the weather allows plants to grow only slowly while the fungus can develop quickly. These conditions occur usually during dry weather when there is not enough soil moisture for good plant growth but there are cool, dewy nights followed by dull days. Plants may be moist for the greater part of the day and this enables the fungus to develop so rapidly that the plants are unable to overcome the attack, as they grow very slowly. Control consists of spraying with bordeaux mixture or copper oxychloride or one of the newer certified therapeutants, such as captan or zineb, which usually give effective control without causing damage as bordeaux sometimes does.. Onions Harvesting and curing of onions for long keeping should be completed as soon as possible as advised in last month’s notes. After March the

weather in most districts becomes progressively less favourable for drying and curing the bulbs. Only sound, well-formed 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. However, 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.

If onions have to be stored outside, a dry, sunless position where there is good air draught is desirable. The onions should be covered against rain and preferably placed on a structure far enough above ground to enable air to circulate under them.

Autumn Sowing

Though autumn sowing of maincrop 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 latermaturing crops, the risks are much less and autumn sowing and subsequent transplanting of the main crop 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 to it about a thirtieth of its

weight of superphosphate and applying it to land on which the crop is to mature. If good-keeping 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 liable 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.

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 by muriate • or sulphate of potash.

The practice of growing onions on the same land for several years in succession has something to commend it, though it probably arose from a recognition of the high fertiliser needs of onions and consequently the desirability of . maintaining very high fertility in an area of the garden regarded as the onion bed. Some trials indicate that onions are likely to do best following cereals, clovers,

or grasses, though they are likely to do better following onions than after most other kinds of vegetables, However, where disease is troublesome rotation is just as important in growing onions as in growing other crops, as root and bulb diseases to which the crop is specially subject tend to build up in soil unless crops are rotated. In addition, 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 gin. deep at’ 10 to 20 seeds per running foot in rows 12in. apart in finely cultivated soil. The g row th of onions, unlike that of most other crops, is not usually

seriously affected by moderate crowding, in the rows. Provided the seed is not sown too thickly thinning should not be necessary on most soils. Good varieties of onions are Ailsa Craig, Straw Spanish (early), and Pukekohe Long Keeper (main crop). Parsley . If an autumn sowing of parsley has

not yet been made, seed can be sown now. Parsley is hardy and will stand the winter without harm anywhere in New Zealand. It is a biennial; that is, it goes to seed the second year. Parsley is usually rather slow to germinate and grow, but it responds well to good soil and to an abundance of nitrogen, Blood and bone at 2oz. to 3oz. to the square yard is a satisfactory fertiliser on most soils.

In most districts seed should be sown early enough to enable the young plants to become well established before the advent of cold weather. Provision is often made for slow germination by sowing a month or even 6 weeks earlier than would otherwise be necessary, but in welldrained, moist soil germination is usually not greatly delayed. Seed sown now is intended in most districts to provide supplies for next spring and summer, because in the well-planned garden parsley will be sown twice a year, in spring and autumn.

Seed can be sown in rows or broadcast on a small plot, but for the best results the plants should be set out about Ift. apart when at the seedling stage. They make quite a good edging and do well in a cool, moist soil in the open or in semi-shade. Aphids are occasionally troublesome, but are readily controlled by spraying with nicotine sulphate 1 : 800 (J fl. oz. plus loz. of soap to 2 gallons of water) or lindane.

Potatoes

Potato crops that are still growing should be kept weed free, but deep hoeing should be avoided, as the roots may be damaged.

Potatoes are mature when the skin of the tuber is firm and does not rub off easily, but while top growth is healthy and vigorous tuber development will continue. The tops therefore give the first indication of crop maturity and should be watched closely, as there is rarely any advantage in leaving the crop undug once maturity has been reached. During wet warm weather, second growth may occur and the tubers may develop knobbly outgrowths, or small, useless tubers may grow at the expense of the large ones. Insect damage is also common.

In the north particularly the potato tuber moth may lay eggs on tubers not properly moulded. Slug damage is not uncommon in New Zealand, particularly when the autumn is wet; millepedes and wireworms too are occasionally troublesome. Loss from insect damage may therefore be considerable. Growing tubers that are attacked by insects occasionally endeavour to grow round the point of attack or source of irritation and the knobbly outgrowths produced (not unlike those resulting from second growth) make such tubers very wasteful in preparation for the table.

In districts where crops are likely to be attacked by late blight they should be sprayed with bordeaux or copper oxychloride or zineb unless digging is to be begun without delay. If potatoes for keeping for several months are dug when immature, there is likely to be heavy loss in storage.

Spinach

Though spinach is usually one of the first subjects for early spring sow-

ing, it is also a useful vegetable for late autumn sowing. It. withstands frost or freezing conditions and it can be sown throughout winter in most districts in well-cultivated soil that is not heavy, provided the seedlings get established. Spinach is generally rated highly as a health-giving vegetable and is quick growing, maturing under favourable conditions in from about 40 to 55 days. It will grow at temperatures only slightly above freezing, though the optimum growth temperature is somewhat higher. Though seed germinates at relatively low temperatures, seedling emergence is usually delayed where there is frequent heavy rain. Spinach is usually classified according to whether the seed is round or prickly and most seedsmen still sell spinach mainly as either prickly seeded or round seeded, though it is preferable to buy named varieties, irrespective of seed type, suited to specific purposes. Prickly seeded spinach is usually sold for winter use, as it is generally considered hardier and more long standing than round seeded. This belief in the superiority of; prickly seeded spinach is not supported by the evidence of trials of different varieties of the two kinds. It has been clearly demonstrated that there are long- and short-standing varieties of both round and prickly seeded spinach. Either may be smooth or savoy (crumpled) leafed. The habit of bolting to seed, which is an inherent factor present to a

greater or less degree in all varieties of spinach, is encouraged by long days and high temperatures. For this reason summer sowing of even the relatively long-standing varieties is not advisable in certain districts. Even the most heat-tolerant varieties will not germinate and grow well in hot, dry weather. When excessively high temperatures are maintained for some time the edges of the leaves, particularly of the older ones, turn yellow. Continuing high temperatures result in the whole leaf turning yellow and the plant is then likely to die of rot or collar disease. Soil Conditions Spinach thrives in cool conditions and in a great range of moist, rich, well-cultivated, and well-drained soils. It is not tolerant of high soil acidity and lime should be applied to most soils that have not been dressed recently, though too much may cause yellowing because of a deficiency or unbalance of certain essential elements such as manganese or iron. A good dressing of organic material such as well-rotted farmyard manure or compost supplemented by a complete fertiliser at IJoz. to 3oz. per square yard is advisable on many gardens. As spinach is a leafy vegetable, extra nitrogen may be supplied by liquid manure or a side dressing of nitrate of soda or sulphate of ammonia raked in along the line of row. Liquid manure is preferable where conditions are inclined to be dry, as abundant

moisture is essential for high yields and good quality; growth should be reasonably quick, as otherwise some varieties tend to be tough.

Seed should be sown thinly Jin. to tin. deep in rows 12in. apart. Plants can be thinned to 4in. to sin. apart in the row, though if seed is sown thinly, very little thinning may be necessary.

The virus disease mosaic sometimes causes reduction in yield.' The first symptoms appear on the youngest leaves as numerous, fairly large, golden yellow flecks accompanied by crinkling. In a few days yellowing becomes general over the leaf. Older leaves wither . at the tips, become yellow, and die. In a few weeks the plant is reduced to a small, stunted rosette of much-crinkled leaves. Infected plants should be removed and burnt. '.

Aphids are probably the most active agents in spreading mosaic, which may be carried over from one season to the next in plants 'of crops such as silver beet, spinach, and beetroot. Aphids should be controlled by regular spraying with nicotine sulphate or lindane.

Winter Greens

Winter greens such as savoy cabbage, cauliflower, or broccoli, fineleaved kale, and leeks should be kept growing strongly.

Pests such as caterpillars should be controlled by spraying with DDT, DDD, or lindane. Aphids and thrips can be controlled by using nicotine or lindane sprays. If conditions are dry, the plants should be watered. On poorer soils liquid manure made from animal manure or sulphate of ammonia at. loz. to about 2 gallons of water should, give improved growth. Alternatively, the soil can be topdressed with sulphate of ammonia at about loz. to the square yard.

Brussels sprouts should be harvested regularly as they reach full size. The bottom sprouts should be gathered first. Leaves should be removed from the base as they • turn . yellow. Plants in exposed situations may have to be staked, as they usually tend to become top-heavy with leaves and sprouts as harvesting progresses.

Various diseases which cause spotting or blotching of the leaves commonly develop on members of the cabbage family toward the end of March. If only a few outer leaves are affected, the trouble may be checked by their removal. Where infection is more advanced protective copper or other fungicidal sprays may be advisable, though most of the diseases which cause forms of leaf spot increase mainly during the cool and moist conditions that occur in late autumn or winter. .