Work in the Home Garden in August

New Zealand Journal of Agriculture, Volume 95, Issue 1, 15 July 1957, Page 45

Work in the Home Garden in August

By

A. G. KENNELLY,

Horticultural Instructor, Department of Agriculture, Dunedin

LJARDY vegetables can be sown in practically all home gardens in August, but the • ■ extent of sowing should be largely governed by the local climate. In many districts soil temperatures for most of August are below those needed for good growth of many vegetables. For that reason extensive sowings should not be made in most areas until September or October.

Temperature is one of the most important factors influencing growth. Home gardeners do not always realise that though temperatures may be relatively high at times during sunny , days early in spring, the. average temperature over 24 hours each day is likely to be considerably lower. As the earth warms comparatively slowly in the relatively brief periods of bright sunshine during late winter and early spring, the soil temperature remains too low in most districts for good growth. For example, the following are the lowest satisfactory temperatures for germination and growth of plants for which first sowings are often made in August: — , Degrees F. Spinach and beet .. . .38 Lettuce . . 39 Beetroot, cabbage, carrot . . 46 Cauliflower, parsley .. 50 Onion, radish .. .. 52

A list recently consulted of 21 stations at which earth temperatures are kept for the meteorological service gave average earth temperatures taken during August over a number of years at 4in. deep. For 17 of them temperatures ranged from 36 to 46 degrees F.; for the remainder no temperatures were above 49 degrees F. This is below or on the borderline of satisfactory temperatures for the growth of many plants. Growth is generally very slow at temperatures lower than 46 degrees F. and even the seed of plants which grow well in relatively cool conditions germinates only slowly at 50 degrees. Seed of most hardy plants germinates well at 60 degrees, but seeds of plants such as tomatoes, melons, and cucumbers need a temperature of about 70 degrees to enable them to germinate vigorously. If seedlings of some plants, notably cabbage, beet, and celery, are subjected to excessively low temperatures for a fortnight or more, premature seed head development (bolting) is

likely. It is not wise therefore to sow too early if there is a doubt about the weather. Seed Protectants Limited protection can be given seed by dusting or coating it by shaking it in a tin with a small amount of suitable protectant, though no seed protectant can give complete protection against all soil-borne disease. Greatest loss of germinating seed is caused by a group of disease organisms known as damping off diseases. These organisms are present in practically all soils and usually thrive under conditions unfavourable for seed germination, such as wet soil and cool weather, which allow them to invade the seed or young plant and cause it to decay. The extent of loss where the seed is coated with protectant usually depends on the degree to which the soil is infected. Some very effective and relatively, new fungicides are now available, such as phygon, thiram, and captan. These may be used as seed protectants instead of the older, more commonly used materials, such as copper compounds. Seeds of beans, beetroot, carrots, cucumbers, lettuces, peas, spinach, silver beet, and tomatoes may be dusted with one of the new fungicides mentioned.

Zinc oxide may be applied in the same way as copper compounds for treating seed of beetroot, brassicas, carrots, lettuces, onions, parsnips, spinach, and tomatoes. Organic mercury dusts are suitable for seed of brassicas, beet, spinach, and pumpkins, marrows, and similar vegetables. Nonmetallic dusts, such as spergon or tetroc, are recommended for pea, bean, maize, carrot, cauliflower, and lettuce seeds. No dressing however, gives more than limited protection, because as a seed germinates and the seedling develops it pushes out more tissue which is not covered by the chemical protectant. Where temperature, nutrients, moisture, and the physical characters of the soil are favourable for growth the seedling usually grows fast enough to resist the attack of most of the weaker soil organisms, but if conditions are unfavourable for growth, newly developed stems and roots may be invaded and one or more types of stem rot, toot rot, or root rot may develop. Sowing and Planting Small sowings of most hardy vegetables can be made in well-drained soils in favourably situated gardens where the ground has warmed enough. .Seed of beetroot, carrots, Chinese cabbage, cauliflower, summer cabbage, kohl rabi, lettuce, leeks, turnips, radish, peas, salsify, scorzonera (black salsify), spinach, silver beet, and parsley and many other herbs can be .sown. Lettuces, silver beet and perpetual or spinach beet, early cabbages, cauliflowers, and onions can be set out in most districts and should mature quickly if strong, well-rooted seedlings .are planted in well-manured soil. In a few districts frost-tender plants such as tomatoes, cucumbers, marrows, pumpkins, and melons can be sown under glass to be ready for setting out when frost danger is past. Though the time taken to produce good plants for setting out varies according to the treatment given, tomatoes started in warm, favourable conditions usually take about 6 weeks from germination .and the other subjects mentioned about half that time to reach a suitable state for planting out. Sowing should be governed by the facilities available and the extent of damaging frost. It is not advisable to have plants ready too early. The date of planting out varies from about midOctober to late October . in some northern districts and to the second week in November in many southern districts. Fertiliser Dressings August is usually a good time to apply a general fertiliser over the garden. Every year a great number of home gardeners seek advice from the local office of the Department of Agriculture on their cultural problems and request analysis of samples of

their garden soil. The charge for analysis is £1 per sample up to 4 samples and the service is intended for commercial growers, as it is most useful for them. Soil analysis is not usually needed by home gardeners. It is probably true to say that apart from faulty cultural practices, pests and diseases, the use of poor seed or seedlings, or unfavourable temperature, light, or moisture, the trouble in at least 80 per cent, of the gardens from which these samples have been taken is that the soils contain insufficient organic matter. Nearly all soils could be improved by the addition of organic matter such as rotted vegetation, that is, compost, garden and household residues and green crops, hay or straw, leafmould, rotted sawdust, or rotted animal residues such as animal or poultry manure or fish, meat, or bone wastes. Plants grown in soils rich in well-rotted organic matter are unlikely to suffer from deficiency diseases. Such soils

are easy to work and crops will succeed in them under conditions which would result in failure if the soils were poor in organic matter. For the highest yields, however, even in soils well supplied with organic matter, it is usually best to apply also the more concentrated mineral or artificial fertilisers. Ideally the home gardener should make up his own combination of fertilisers to suit his particular soil and to suit the needs of the plants he intends to grow. However, this is usually impracticable, as most home gardeners grow a wide range of plants which vary in their nitrogen, phosphorus, and potash needs. There is, too, the difficulty of assessing the nutrient status of home garden soils, which have often had different past treatment, in different parts of the garden. Results are usually satisfactory on soils adequately supplied with organic matter if the home gardener applies a good general or so-called complete fertiliser rich in nitrogen, phosphorus, and potash. One with a ratio of 1 : 2 : 1 which is likely to give good results on

a wide range of soils can be made up as follows: — . Parts by weight Blood and bone . . 7 Superphosphate . . . . 7 Dried blood . . . . . . 2 Sulphate of ammonia . . 2 Sulphate (or muriate) of potash . . .. . . 2 Leafy vegetables have a high nitrogen requirement, so that .if the above mixture is used as a base dressing for them, it should be supplemented with side dressings of a combined fertiliser with a higher proportion of nitrogen. Where there is evidence of specific deficiencies further suitable materials can be added, for example, magnesium sulphate (Epsom-salt) for magnesium deficiency and molybdenised superphosphate for molybdenum deficiency, which causes whiptail of cauliflower. Such mixtures can be dissolved and watered on as sprays or side dressings according to which is most appropriate. Fertiliser Quantities Commercial growers usually calculate their fertiliser applications at a given number of hundredweights per acre. The more concentrated mineral fertilisers are usually applied at lcwt. to 2cwt. per acre, mixed fertilisers at 2cwt. to 4cwt. per acre or more according to need, and organic fertilisers such as blood and bone at up to i ton to 1 ton, or even more sometimes. Home gardeners can assess comparative dressings per lineal or square yard from the following:— Broadcasting fertiliser: About Jib. per square yard (actually 7-joz.) equals 1 ton per acre; loz. per square yard equals approximately 2|cwt. per acre (actually 302|1b.). Fertiliser in bands: Applied in rows 2ft. 6in. apart loz. to 9| lineal feet of row equals lewt. per acre. Applied to rows 2ft. apart, loz. to 12 lineal feet of row equals lcwt. per acre. Asparagus, Broad Beans, Leeks, Cabbages, Cauliflowers Asparagus can now be set out. Some notes on its culture, together with seasonal notes appropriate also to August for broad bean, leek, cabbage, and cauliflower sowings, were given in last month’s “Journal”. 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. Apart from the need of a well-cultivated, highly fertile soil, one reason for the lack of success is that seed does not germinate well in cold conditions and seedlings are likely to damp off owing

to fungous diseases in wet soil. Where drainage is poor and soil conditions are cold, a raised bed is advisable and for convenience in cultivating and harvesting the bed should not be more than about 3ft. wide. Manuring Soil heavily manured for the previous crop is best for carrots, and sandy or light loams are especially suitable for early crops. Much experimental work has been done on the manuring and production of carrots and it has been shown that for best results the soil must contain adequate phosphateusually applied as superphosphate. Generally the application of potash is much less important, at least for early carrots, and only moderate amounts of nitrogen should be needed on most soils. A fertiliser made up for instance by mixing (by weight) 2 parts of sulphate of ammonia, 8 parts of superphosphate, and | to 1 part of muriate or sulphate of potash usually gives good results. On most soils such a dressing should be applied at 2oz. to 3oz. per square yard. Carrots are fairly tolerant of acid conditions, but where a deficiency of lime is suspected it can be remedied on most soils by the application of 2oz. to 3oz. of lime per square yard. Splitting Splitting of carrot roots is a widespread trouble and generally is most prevalent in the stump rooted varieties. Wide spacing, which also results

in lower yields, tends to give a greater number of split and coarse roots, as also does excess nitrogen. Splitting is more prevalent in dry conditions and with early sowing or if the roots are left relatively long in the ground. Soil Conditions Soil for carrots should be of good texture. If it bakes or forms a crust after rain, emergence and growth .of seedlings may be adversely affected. Heavy soils on which growth is comparatively slow tend to produce thick, short carrots with greater core development and inferior 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 roots 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. Carotene content is higher in some varieties than in others, but is also influenced by

temperature and availability of plant food. Irregular moisture supply and high temperatures 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 |in. to fin. . deep, according to whether the soil is heavy or light, in rows about 12in. apart. A quarter of an ounce of seed should sow about 100 ft. of row. If the soil is light and free, there should be no need to thin, but on heavier soils young plants’ 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. 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. Varieties Good varieties include Chantenay, Taranaki Strong Top, Nantes, and Morse Bunching. Scarlet Horn is widely used where a quick-maturing carrot is wanted. Kohl Rabi Kohl rabi belongs to the cabbage family and many people consider its flavour superior to that of cabbage, as it combines the flavours of both cabbage and turnips. It is treated as a root vegetable, though it is not a root vegetable in the sense that carrots and turnips are. Its bulbous edible “root” is an enlarged stem which forms above the ground. To secure tender, succulent bulbs kohlrabi should be grown quickly. It should be used before it grows beyond about 3in. in diameter, because if left to reach maturity, it becomes tough and stringy. It grows well in a soil that is well drained and reasonably rich in humus. Though kohlrabi is often classed with turnips, it does

well under a wider variety of conditions; generally its requirements are similar to those of summer cabbage. Kohl rabi is usually grown as a coolweather vegetable, but is very useful as a substitute for turnips during hot, dry weather, when turnips are likely to fail, though even kohl rabi should not be permitted to become too dry or it may have a bitter flavour. Kohl rabi is very hardy, but the bulbs do not keep well when stored. Seedlings transplant well, but it is usually preferable to sow the seed Jin. deep in rows 12in. to 15in. apart and later thin the plants to stand 6in. to Sin. apart in the rows rather than to transplant them. Plants mature in from 8 to 12 weeks from sowing. Good varieties include White Vienna, Purple Vienna, and Short Top Green. Onions In most northern districts or where it is customary to sow the main crop in autumn, onion plants can be set out 3in. to 4in. apart in rows 12in. apart in August. In most southern districts the main crop is sown in September, but in favourably situated gardens where soil conditions are good a small early sowing may be made toward the end of August. Peas Where soil conditions are favourable a sowing of peas can be made in August. A quick-maturing variety, such as William Massey or Little Marvel, is usually preferred. Peas thrive in cool but not cold conditions

and a moist, deeply cultivated, welldrained soil containing adequate humus is best. Soil preparation should be thorough. The ground should be dug deeply and where necessary organic material such as compost or farmyard manure should be incorporated, preferably some time before sowing, though peas usually do best following a crop that was well manured with organic and inorganic manure. The addition of superphosphate at loz. to 2oz. per square yard has proved beneficial on many of the heavier soils that have been kept in good condition by adequate manuring with organic material or by the digging in of green crops. On the lighter soils a complete fertiliser is likely to give better results. Only moderate fertiliser applications are advised on soils in reasonably good condition. Too-heavy manuring, particularly with nitrogenous organic manures, tends to promote excessive foliage growth and makes the crop more liable to disease. Lime is essential for peas on most soils. It can be supplied by an annual dressing of 3oz. to 4oz. of carbonate of lime per square yard. Sowing Seed Seed should be sown in V-shaped or broad, flat drills, usually drawn out with the hoe. Drills should be 2in. to 3in. deep, except where conditions become hot and dry, when they should be considerably deeper so that, though the seed should not be covered with more than 2in. of soil, the roots will be well down in the cooler and moister soil of the lower levels. This is very

important where conditions are dry or where heavy wind is likely, as the plants can to some extent be gradually earthed up the stems as they develop. Dwarf varieties should require no other support. In many districts newly emerged peas must be protected against birds, though birds are mainly troublesome in early spring, when food is scarce and is lacking in variety. Pea guards made of wire netting are most effective, provided the ends are blocked, but they should be removed before the peas become entangled in the wire. Cotton stretched over the shoots is effective if a number of strands, which may be criss-crossed or stretched in parallel lines, are used. Numerous other methods of protection are effective if well applied. Rhubarb August is a good month to establish a new rhubarb bed or to break up and replant an old one. Rhubarb is hardy, easy to grow, and yields heavily if well supplied with moisture and plant foods. The soil should be well drained and preferably well supplied with organic matter. The lighter soils that dry out are less suitable than the heavier, well-drained soils. In New Zealand varieties can be grouped as early, main-crop, and everbearing, though in good soils that do not dry out most varieties can be grown throughout the year. Rhubarb can be raised from seed, which is usually sown in spring as soon as the soil has warmed enough, but to obtain varieties true to name plants for new plantations must be obtained from the breaking up of existing crowns. Except in especially favoured situations rhubarb should preferably be lifted every 4 or 5 years, as the large roots or crowns tend to become hollow and weakened if undisturbed for longer periods. After lifting, the crowns should be divided with a sharp spade. Replanting Single crowns each with a piece of root attached should be replanted. If set with the. tops of the crowns about lin. below the soil surface, plants should develop well in a season. Crowns should be set out 24in. to 30in. apart in rows 30in. to 36in. apart according to the vigour of the variety. Unless plants are. very vigorous, they should not be harvested until the second season after planting. In harvesting, the leaf stalk is grasped near the base and pulled with a twisting motion. Plants should not be denuded of their foliage, nor should they be harvested for too long without an adequate rest period during which a good growth of leaves is permitted to flourish to build up the plants’ reserves.

Manuring Established beds need little attention, but should be kept weed free. Unless the soil is in very good condition, it should be dressed in the dormant season with organic material such as farmyard, stable, or poultry manure or compost. Alternatively blood and bone at 4oz. to 6oz. to the square yard gives good results on soils that are well supplied with moisture and of good tilth. In addition liquid manure or two or three applications of sulphate of ammonia or dried blood at loz. to the square yard may. be advisable. However, as early dying down of the leaves and ripening of the crowns are usually important for early and maincrop rhubarb in districts where the top growth dies down, it is not advisable to apply stimulating fertilisers later than immediately after the last pulling. A neutral to medium acid soil suits rhubarb and on most soils 2oz. to 4oz. of lime a square yard every 2 or 3 years gives satisfactory results. Rhubarb can be forced by covering the crown with boxes or straw. An early variety should be chosen. Forced rhubarb has less development of the leaf blade and the stalks are more tender and sweet. Varieties There are many good varieties of rhubarb on the market and a selection may be made of early, main-crop, and ever-bearing varieties. It is advisable to choose a variety the quality and vigour of which are known to be good. Shallots It is something of a tradition among home gardeners that shallots should be planted on the shortest day and harvested on the longest. However, if soil conditions are favourable, shallots can be planted any time from late autumn until early spring. The keeping . quality of different varieties varies. Some start growing much earlier than others, and if held out of the ground, should be planted before they exhaust themselves producing leaves, though usually under good conditions even specimens that have become very wizened will produce a good crop. Soil and Manure Shallots succeed in almost any garden soil, but prefer a well-drained, fertile soil rich in well-rotted organic matter. Heavy clay soils that dry out excessively or are poorly drained are least likely to give good results. To avoid the build-up of disease crop rotation should be practised. Shallots should not follow other members of the onion family. Manurial requirements are moderate and shallots grow well in soils that were heavily manured for a previous

crop. Where additional fertiliser is needed a dressing of equal parts of blood and bone and superphosphate applied at 2oz. to 4oz. to the square yard, according to the fertility of the soil, will usually give good results. In districts of average to high rainfall growth in most soils not recently limed is likely to be improved by carbonate of lime at 3oz. to 4oz. to the square yard, preferably well worked in some time before planting. Planting Soil should be cultivated to a fine, friable, tilth and should be firmed. The rows should be marked or drills drawn and the bulbs or cloves, graded in size, should be pressed far enough into the ground to stabilise them, usually Jin., though deeper planting, even up to the neck, is sometimes preferred. Bulbs should be set sin. to Bin. apart, according to the vigour of the variety, in rows not less than 12in. apart. They soon develop roots and as they grow divide into a number of cloves or offsets which remain attached at the base. There is little advantage in planting large bulbs unless a • great number of small cloves is wanted. Medium to small bulbs generally do not yield as heavily as large bulbs, but they usually yield more large bulbs. Shallots can be grown from seed sown in spring as onions are. Seed has not been noticed listed in local catalogues, though it is listed in some from overseas. Such seed, however, is rarely that of the true shallot. Usually it is seed of a small variety of onion, which if left in the ground, goes to seed as other onions do. Cultivation After establishment shallots should need no other attention than weeding. If the soil becomes compacted and aeration is restricted, cultivation may be required.

Guide on Spray Materials A large number of new materials for controlling pests and diseases of plants and trees has become available in recent years, and though many of them are more effective than the older spray materials, it is necessary to understand clearly their specific uses. For that reason Bulletin No. 390, “Disease and Pest Control in Orchards and Gardens”, which has just been published by the Department of Agriculture, should be welcomed. The bulletin, compiled by Dr. H. Jacks, formerly Senior Plant Pathologist of the Plant Diseases Division of the Department of Scientific and Industrial Research, is available free from offices of the Department of Agriculture.