Second Year Care of the Dr. Rock Seedlings
The early part of May, providing you do not live in a district plagued by late frosts is the ideal time to transplant the small rhododendron seedlings from their first year flats or containers.
Many of these plants will still be small due to their dwarf nature, others will in comparison be quite large, especially varieties that represent the tree types. All should be planted outdoors this season after growing the first year of their life under glass or other protection.
The gardener should not dawdle, but at the first opportunity in he spring, cultivate a portion of the garden suitably adopted for these seedlings. I cannot help but try to impress the necessity of well cultivated, conditioned soil, and early planting. Seedlings planted in May will establish themselves and make several growths during the year, whereas seedlings allowed to make another growth in their flats without being transplanted will be injured and stunted in the first all important year in the open. Seedlings planted several months later will be forced to face the dryness and heat of summer immediately upon being set outdoors. I have observed seedlings planted in early May almost make double the growth of those planted in June or July.
It should be the goal of the gardener to see that these small plants be given the best possible care this first year, and I consider proper location and soil condition along with the correct transplant time very important.
In the preparation of the bed for the seedlings, I would like to mention that the addition of peat moss should of course, be considered the optimum medium as a soil conditioner. It is almost foolproof and carries none of the pitfalls so often encountered in using other materials. Many times one reads and also hears of using other material, oak leaves, leaf mold, woods topsoil, chopped sod, and sawdust, mention only a few. I recall during the war peat moss was almost unobtainable, so as a substitute I added several wheelbarrow loads of rich appearing mulch gathered in the forest. The mulch was worked into the soil of a small bed that was being prepared for small rhododendron seedlings. For one reason or another these plants were most reluctant to advance, and by fall many had been lost. Later upon the visit of a friend, also interested in rhododendron, it was called to my attention that a great many of the plants apparently were dead. None of the plants were in a thrifty condition though they had been well cared for. We dug up several and noticed the soil covered with a grayish mold, the mycelium pervading to a depth to which the mulch had been added. The tiny plants had not expanded their root system in this medium, whether the mold was a factor I do not know, but plants in one single row of peat moss planted on the edge of the bed were in excellent condition.
The use of sawdust particularly with small plants should be avoided. Many gardeners use sawdust, and by the addition of nitrogen seem to make a success of its application as a mulch or soil conditioner. The hazard of how much nitrogen to apply is sheer guesswork at best. If more nitrogen is applied than can be utilized, the small plants could very easily be casualties. If not enough is used the plants will literally be starved.
Small seedlings should be planted close together in partial shade, and by planting these tiny seedlings about four to six inches apart the problem of their care is minimized. Weeding, shading and watering are much less of a problem if the plants are localized. Don't make the mistake of planting these year old plants about the garden or woodland as single specimens, for they are still too small to withstand the hot sun, and can easily be lost if not watered. If you grow your seedlings well this year they may be transplanted in a permanent position or location this autumn.
It is still important to keep the plants well watered this first year. If the soil has had ample peat moss added to it in its preparation the seedlings lose no time in making and establishing a root system. The moisture retaining qualities of the peat moss will lessen the watering chore experienced during the past summer, when missing a turn at watering might have been fatal to the seedlings. In general you-will find that the plants this season will require less of your care and attention, but outright neglect is still out of order.
Watch the plants closely for attacks from pests. Discolored or spotted foliage should be investigated, and if infested by insects, remedial measures should be employed. Illustrations and article on these rhododendron pests will be found in the Quarterly Bulletin of the American Rhododendron Society, Vol. 3, No. 1. Illustrations Nos. 1, 2 and 3.