Getting the Best Blooms from Your Chrysanthemums: Building the Framework
THE months of May, June and July and into the early days of August is the period of greatest growth, and the aim is to further that growth without promoting soft and sappy stems. The best blooms are produced on well-ripened wood, and the mid-summer culture is designed to give just that. Plants which have been hardened off may be moved out of the frames in early May in most districts, though in our fickleit may be wise to keep some hessian or similar material handy to throw over the plants if frost threatens. If well hardened the plants will stand a slight nip, but it is best to take no risks. A convenient method at this stage is to stand each plant in the pot it will finally occupy. A certain amount of protection is thereby given from wind, and a further advantage is that the grower can allocate final pots to the plants most suited to the various sizes. It is a great mistake to give too large a pot, and the size must be decided by root development. If the rooting system is strong use the larger pots up to 10 inches in diameter, but where rooting is weaker or where the plant was late-rooted give the smaller sizes; even down to 8 inches, which will give good results particularly if the crop is reduced a little as well. If in doubt, use the smaller pot, for a pot-bound plant can be fed early to maintain growth, but soil unoccupied by roots soon becomes sour and there is little to be done short of complete repotting —a most critical operation.
The date of final potting will also be decided by the extent of rooting. When the 6-inch pots are nicely full of roots the plants should be moved on, but this stage will be reached at different times according to variety, time of rooting, etc. It is, therefore, necessary to treat each plant separately, moving it when required, and the potting of a normal batch may spread over a month. Forget the calendar and be guided by the state of the stock, but usually the work is done between mid-May and early June.
Final potting is a most important matter, and it should not be hurried or skimped. The compost will have been mixed a week or so previously, and should be kept in a dry place, as it must not be used if at all wet and sticky. Turn it about with the shovel occasionally in the waiting period, and it should be in perfect condition for the job. Pots must be clean, but the scrubbing is best done in November when the grime is easier to remove. If they are soaked overnight in a tank of water to which some disinfectant has been added, moderate pressure with the brush will remove every stain. A good supply of crocks in various sizes must be available, and these also should be clean, having been sterilized in boiling water. When the pot has been crocked as indicated earlier, follow on with the compost well pressed down to such a level as will leave the old soil surface about 3 inches below the rim of the pot. The plant, having been watered the day before, is turned out and stood centrally on a slight mound as new compost is added. Now, this potting must be fairly firm and a rammer is used, but it is a great mistake to fill the pot and then ram from the top. Let every inch or so of the new compost be firmed as it is added, and aim at an even consistency throughout the pot. It is difficult to indicate how hard one should ram except to say that the label should need a good thumb pressure to drive it home. Another indication will be evident when the first watering is given some 7 days later, for the water should take up to two minutes to disappear. Keep the rammer close to the pot side to avoid damage to the roots. This process recalls the traditional instruction to make the final compost rather coarse with lumps as big as walnuts. When these lumps come under the rammer they break up and form undrained and unfertilized pockets, and it would seem a better plan to have an even compost, not too coarse, and rely on the sand andto keep it open and sweet. Finish the job neatly, leaving a full 3 inches for watering and later top-dressings. Insert a cane of suitable height well away from the old soil ball and loop the plant securely to it. If the compost was in the right condition, no watering will be required. Stand the plants pot thick in a sheltered spot, and correct any tendency to flag with a light spray. When this is obviously insufficient give the whole batch a good watering, and thereafter each plant should be watered as it requires it.
Remove Side Shoots and Extra Stems
All unwanted side shoots must be removed as they appear, and the extra stems left on as insurance against accident should be removed by the end of June so as to direct all the plant’s energy into the final framework. Once the plants are established in the new soil they can be moved to the summer quarters, an open site with maximum light. By the time the September gales come along, the plants will be quite large, and it is well to bear this in mind when erecting supports.
Take Precautions against Wind Damage
Each row of plants should be securely tied to strong wires stretched between substantial posts driven well into the ground at each end. Ideally there should be a post every 10 feet in a long row. One wire about 4 feet from the ground and another just above pot level will ensure safety. The main stake only need be tied to the wires and furtherlooped to this solid centre. Give as much room as possible, with at least 2 feet 6 inches between the rows and with no plant touching its neighbour in the row. The more room given the better the growth. Birds may use the wires as landing grounds from which they may eat the growing points, and black cotton stretched an inch or so above the upper wire will save much heartbreak.
Water with Care
Growth is now rapid and the demand for water increases. Go over the whole stock, say, twice a day and water when needed. Never try to save trouble by watering the whole batch at once irrespective of individual needs, for such methods are fatal to success. If ripened wood is to be produced the plant must be allowed to dry out a little before water is given, provided that this condition is not left so long as to cause flagging. In hot weather the plants will revel in an overhead spray of cold water late in the afternoon, though this must not be overdone.
Feed at Frequent Intervals
About five weeks after final potting the plant will have used up the greater part of the available plant food in the compost, and further supplies must be added. Feeds may be in liquid form or given dry and watered in. For various reasons the liquid types are most reliable, but in persistently wet periods the drycan be given to be washed in by the rain. The novice is strongly advised to use one of the well-known proprietary brands, keeping clear of any strong stimulants like sulphate of ammonia. Keep well within the maker’s directions, for double amounts often do more harm than good. Perhaps it will be best to lay down certain principles and leave the reader to work out his own plan. 1. Use only balanced fertilizers and watch the proportions of nitrogen and potash. In the period of rapid growth let the proportion be about 2 of nitrogen to 1 of potash, but in dull weather and always after the bud has been secured let the potash increase almost to the same level as the nitrogen. One popular range of fertilizers contain these two elements in the proportion of 8 :3 in the first mixture and 6 :5 in the second. 2. Begin with weak doses and gradually increase to the full amount recommended by the makers. 3. Half doses given frequently will give better results than full doses at longer intervals. 4. Never feed a dry plant. Water well first and then give the . 5. Further help can be given by top-dressing with fresh compost of the same formula as that used for the final potting. Perhaps one in early August, one in late August and a final one just before housing would be about right. Some authorities suggest that no feeds should be given for a week or more after top-dressing, but if liquid fertilizers are used it is both safe and beneficial to continue feeding if only to reach the lower roots. Each dressing may be about 2 inch deep and should be firmed gently with the hand. The wisdom of having a rose on the can is obvious at this point.
The tying-in of growths must be seen to regularly, as should the removal of all surplus growth with a view to concentrating energy in the chosen stems.