The ‘Spencer’ type, trained up canes in `cordon fashion’, will grow to a height of 14 ft. though this means that all side shoots need to be removed during the growing season and every few days there is the business of tying or ringing the thick haulms (stems), and once or twice during the growing season kneeing, or layering is called for. On the other hand, if the sweet pea is allowed to go its own way brushwood or wire to the height of 8 ft. will not be too tall. Soils Land enriched with farmyard manure at the rate of one barrowful to each strip of 15 ft. by 4 ft., dug in the fall or early winter into the second spit of soil and fortified by 1/2 lb. of bonemeal, will give the best results, or good garden compost at the same rate will serve. Failing that peatmoss may be used. A big bucketful to the square yard, fortified by a1/4 lb. of artificial fertilizer containing nitrogen, phosphates and potash in the ratio of 20.10.10, obtainable in granular form, has proved a very good substitute.
The whole area where the sweet peas are to be grown should be double-dug and the bottom spit treated as suggested. If the soil has been used the previous year for a crop that has been manured, nothing at all need be added. Acid soils should be given a light dusting of lime in early spring. Sweet peas revel in sunshine and dislike drafts, so give them a sheltered place.
When to Plant Where winters are less severe, seeds may be sown in November providing a covering of salt hay is given during the winter. In colder areas sow as early as possible in spring. A spring sowing may also be made in pots or flats in a greenhouse six weeks in advance of planting time. Sowing Six seeds to a 6-in. pot, sown an inch from the edge is ideal; or of flats are used sow the seeds 2 in. apart each way. Sow 3/4 in. deep. Use a moist compost of 3 parts of sieved loam, 1 part of peatmoss and 1 part of coarse sand. Cover the pots or flats with thick layers of paper to prevent drying out. Set a couple of mouse traps, for mice find the seeds irresistible. Inspect after a week and as soon as the shoots appear remove the paper. Water if necessary, and after a day or two start to give plenty of ventilation on all suitable days.
When the plants have four leaves pinch out the growing points to induce side shoots. When these are 1.5 in. long, harden off the plants by placing the pots or flats in a frame or under the south wall of the greenhouse.
When sowing directly outdoors the seeds
Planting Never plant out plants raised in the greenhouse until the soil on the plot has been reduced to a fine tilth. Then erect the canes if the plants are to be grown cordon style. A strong support at each end of each row will be necessary, with a cross-bar at a height of 5 ft. Double rows, 2 ft. apart, are best, as this helps when it is time to layer. Stretch strong wire from the end of each cross-bar, insert 8 ft. tall canes, 7 in. apart and secure them to the wire.
Using a trowel, make holes to receive the plants on the outside of each cane, to facilitate layering. If the plants are to be in circles, they should be planted inside the circle of brushwood. If a circle of netting is to be made, plant first and surround with the netting. Spread the roots and return the soil, so that it just covers the white collar of the plant. If a plant has a brown collar, reject it. It may grow to a height of 3 or 4 ft. and then collapse. Always surround each plant with small twigs. Black thread stretched across the twigs will deter birds.
The Climbing Plants May is a month of vigorous growth. The cordon plants by now will have been restricted to a solitary stem by removing the weaker of the side shoots, of which there may be three or more. Tie in the early stages, very loosely, using raffia. At 1 ft. in height the big sweet pea metal rings may be used. Pinch out side shoots and tendrils to channel the sap into the one stem.
When the plants are grown ‘naturally’ side shoots are left alone and the tendrils are not removed.
Watering Never allow the land or the plants to become dry. Water the former and spray the latter.
Bud-drop Early in the season buds which should develop into flowers sometimes assume a frozen appearance and drop off. This is not a disease and eventually nature will correct the trouble. It will even occur, on occasion, in the middle of the flowering season. It is caused by hot days and cold nights, or excessive rain, and there is nothing to worry about.
Kneeing or Layering
The stems are laid in a row close to the line of canes. Each plant will lift up its head within a few hours and within three days it will be possible to start the tying process again. Flower stems at first will be twisted and should be cut off, but once the plants have grown a foot or so up the canes, if they are kept tied, the stems will be just as straight as previously, and there is still another 6 ft. or more of cane for them to climb.
The Natural Method
Recommended Sweet Pea Varieties
The following is a list of ‘Spencer’ sweet peas, good exhibition varieties and also splendid for decorative purposes, chosen from hundreds of named varieties. Where two or three of the same color are named there is not much to choose between them. White: ‘White Leamington’; ‘White Ensign’; “Majesty’. Cream: ‘Hunter’s Moon’; ‘Margot’. Picotee: ‘Selena’; ‘Tell Tale’.