CULTIVATION OF THE DAHLIA

Otago Daily Times, Issue 22742, 30 November 1935, Page 23

CULTIVATION OF THE DAHLIA

FOR GARDEN AND EXHIBITION The dahlia grows magnificently here in New Zealand, and adapts itself to almost all soil conditions, from the light, sandy loam to the heavy and sticky clay soils. There is hardly any other class of plants which produces such a wealth of gorgeous blooms and has such a long flowering period. They may be had in bloom here in Otago from the end of December until cut down by frost in April or May. For general garden decoration they have no equal. In growing dahlias for general garden purposes, the first essential is to see that they are in a well-drained position, and that they have a fairly sunny position, preferably sheltered from the west and south. There is more harm done to dahlias from a few hours in the evening sun than during any other part of the day. In the event of having a heavy soil, this should be well broken up and plenty of old rotted vegetable matter, such as ■weeds and grass, added to help in keeping the soil cool and loose, and thus absorbing and holding the moisture. A good plan is to prepare the bed a few weeks before planting, by digging it over a few times, adding the decayed vegetable matter and a good handful of bonemeal to the square yard. PLACING THE STAKES. After having turned the soil over several times and reduced it to a fine tilth, it is now time to place the stakes. These should preferably be for tall varieties 6ft by lin by lin, and shorter ones should be used for the more dwarf varieties. A few days before planting it is a good plan to give a light dusting all over with air-slaked lime, and this chipped in and then watered when dry. The plants may now be put in, taking care always to have the taller varieties at the back and the more dwarf varieties in front. To keep the plants from growing too tall, when about 2ft high the tops should be pinched out, thus keeping the plants compact and bushy, and thus producing a profusion of blooms. This is an opportune time for giving a good top-dressing of well-decayed animal manure. If

larger blooms are required, this may be had by pruning and disbudding, but for general garden purposes this is not always desirable. CULTIVATION OF BLOOMS FOR EXHIBITION. In growing the plants for exhibition, they require different treatment to the foregoing altogether. The first step in this is cultivation; second, disbudding and thinning of branches. There is a good deal of controversy regarding which are the best to use for exhibition —that is; tubers or green plants. My experience is that either tubers or plants are equally suitable, and the best of exhibition blooms may be had from either. The only reasons for using green plants are that tubers arc not always procurable just at the time they are required, such as, for instance, a grower who does not wish to plant till end of December would find it very difficult to secure tubers of all the varieties required. For my part, I prefer plants at any time, for the reason that if tubers are planted there is no guarantee that they will grow, and a grower ie waiting for it to show up for perhaps weeks before investigating to see the cause of nonappearance. with the result that if not rotted, perhaps the shoot gets broken off during investigations, and, therefore, all this time is lost, which would not happen if a plant were used, because it can be seen at a glance at any time after planting if there ie anything wrong, and remedial measures taken at once. We will now presume that all the soil preparations have been thoroughly carried out. and we are now planting. If planting tubers, these should be at least 4in below the surface, and should not be watered too much beyond seeing that the soil is moist until they are at least Gin above the surface. Otherwise too much watering ie liable to rpt the tubers, and does not assist them in any way, as Nature has already seen to this by the supply of food carried in the tuber, which is sufficient to carry it on until rooted. In planting green plants, the soil should be just moist, but not damp enough to prevent it rollin'* back into the hole while being opened. If you are in the happy position of being able to select your plants from a fairly large stock, great care should be taken to select only those that are vigorous and sturdy, stocky plants, and

which have not been potted for more than four weeks if at all possible. The reason for this being that the longer they are in pots the more twisted will be your tubers, which is a very real disadvantage when dividing or propagating the following season. There are two ways to plant a green plant; one is the right way, the other the wrong way. Some people think that when the plant is removed from the P ot it should be planted immediately, without disturbing the soil in any way. Now this is altogether wrong, as will be shown. In planting this way the roots and tubers are all tangled and twisted together in the soil, just as taken from the pot, and this soil, in most cases, is dead and deficient in any plant-building properties. This means that new roots have to be grown and sent out in the surrounding soil to get the nourishment needed to build up the plant and start it growing. In the process of sending out these new roots the plant is dormant for about two to three weeks generally. Now this is a waste of time to the grower and a menace to the vitality of the plant, which is usually lowered, thus causing it to become the prey of any or all insect pests and diseases which may be about. The correct way to handle the plants is as follows: —The soil in the pots should be sufficiently moist to allow the plant to be knocked out without _ any roots sticking to the pot and becoming broken. A bucket or big dish of water should be handy, and holding the plant upright in the palm of the hand and gently moving it up and down in the water the soil is .all washed out, leaving the roots bare. Spread roots out in hole the same as a rose or fruit tree; and then fill in the soil and water, care being taken to plant no deeper than it was in the pot. If this ie not attended to, the result is, if the weather is at all hot, the plants get what is known as scald, and drop over from the level of the ground. It is a good plan when planting if plants are big enough to pinch out the top. leaving room for as many laterals as it is desired to work on. It is purely a matter for the individual grower how many blooms the plant is required to produce. Borne growers prefer four, some six, and some eight and ten. It all depends on the preparation of the soil and the feeding that is given how many blooms can be carried on the one bush. I am not a believer in over-feeding or '

forcing my plants to produce large numbers of big blooms at the one time, but would rather feed sparingly and have the blooms coming along singly. Overfeeding and forcing dahlias continuously for the whole season and then dividing or propagating the same stock again the next season is, in my opinion, one of the main causes why so many dahlias are a complete failure after the first two seasons. Having made up your mind how many flowers you require your bushes to carry you pinch out the tops accordingly, and as the laterals appear and begin to lengthen out they should be secured to stakes by tying with some soft material to save them being broken off by winds. When the plants are about 2ft high, they will benefit by a good mulch of wellrotted cow manure. In doing this, I find that it is best to chip this in lightly with the top soil. This prevents the manure caking down and preventing the water from going through, and it also helps in the decomposition of the manure much quicker. As soon as the buds appear, and they are large enough to pick off, the lateral or two side buds should be pinched out, leaving the centre or crown bud. There arc some varieties which it is preferable to pinch out the crown bud and leave the side buds or a lower lateral to grow on, such as Croydon Perfection, John Casey, and several other varieties which naturally have short stems on crown buds. This method gives much longer stems, and in some varieties fuller blooms. These can be found out by experimenting with the different varieties. There are many different mixtures used by different growers for forcing and keeping up the size of blooms for show purposes. Some growers overdo it, and spoil their blooms, and cannot understand why they never get good blooms. One method of feeding is a dressing of superphosphate No. 5 one week and alternate iveeke_ one of blood and bone, very lightly. No. 2 is about six parts of bonemeal. two superphosphate, one potash, one sulphate of ammonia. No. 3 is four parts blood and bone, four super., two potash, and two sulphate ammonia. No. 4. five super, five boncdnst. two potash, two sulphate ammonia. When the buds are beginning to open up is the time to be preparing to cover them from the rain, dew, and sun. There are many methods of covering, such as old umbrellas, etc. These are very good,

but, owing to being so large, they prevent the rain or the watering from getting round the plant. Another method is a cover over a wire frame, much like a fern basket, only larger, and yet another is by boxes with adjustable flaps or blinds, which may be raised or lowered at will. CUTTING THE BLOOMS. When blooms are ready for exhibition, they should be cut in the evening previous to show, and end of stem dipped in boiling water to a depth of lin, and then plunged in cold water and stored in a dark room until ready for packing. —By G. W. Cooper, before the Dahlia Society of N.S.W., published in the Australian Garden Lover.