Potting or No Potting
F. W. Schumacher, Sandwich, Mass.
Potting rhododendron plants grown from cuttings or seed is the commendable practice of the professional grower raising plants for sale. There is no denying that attractive plants can be grown in pots by repotting to larger containers when needed but such plants put out into the open have a difficult time to adjust. There is no question that rooting cuttings on a large scale requires greenhouse conditions with bottom heat.
Are these practices commendable to the lay gardener who grows a limited number of cuttings and grows seedlings and put them in pots? In my opinion it is certainly not. Seedlings and cuttings can be raised without heat and should not be potted for best and quickest results.
Potting up young plants cripples their root system from the very beginning, same as the feet-binding custom in China in the past crippled the feet of many unfortunate women. Plants from pots lined out in nursery rows in the open stay put for some time unable to cope with natural conditions. Breaking up solid root balls from pots can really be done only by vertical slits made around with a knife. This means, of course, destruction of many roots - which plants have to replace but slitting may be better than no slitting at all. We had good results here in the favorable climate of Cape Cod on our place on a hill on loam or sandy loam soil within sight of the sea growing plants from seed as follows:
Seeding in early spring to fall in cold pit. pricking seedlings any time in pots or boxes. Pit is not heated and will freeze in cold weather with containers frost bound occasionally for weeks. Two year seedlings are transferred to 4 ft. beds under lath shade in shade house any time spring to August. When 8-10 inches high seedlings anytime from spring to September go into nursery rows. There is no overhead shade or irrigation. We water only when absolutely necessary in a severe dry spell.
This year seedlings were lined out in July and August receiving one watering right in the holes at planting time. There were intermittent rains and the seedlings responded without trouble. Had these seedlings come from potted stock, they would have needed constant attention.
We learned a lesson from plants under drought conditions. Where the soil was cultivated clean between plants and rows, plants perished, whereas in not cultivated row plants surrounded by grass and weed growth did not suffer, favored apparently by the nightly dew precipitation on plants and the surrounding weed growth.
In contrast to deciduous azaleas, rhododendrons and the so called evergreen azaleas, on account of their near succulent leaf structure. are really quite drought resistant.
On our grounds - which had been cultivated years ago or have been under grass, the dog or quack grass, Agrophron repens, with its - wiry roots, is omnipresent. It can easily be killed with chemicals before plowing but who wants to take a chance with soil pollution from weed killers. The quack grass roots are raked out after tilling to the best of our ability but sections of root are always left in the ground and every section from each of its inch internodes is capable of starting a new plant. We have given up the struggle of dog grass intervention between nursery rows and let it come back after a while where it is quickly joined with seedlings of velvetgrass, Holcus lanatus, which is coming up everywhere the ground has been tilled. We do look out for Goldenrod, Solidago species, and Tansy, Tanacetum vulgare, seedlings. These are the worst perennial plant pests in these parts. They come up everywhere between naturalized large rhododendron plants and cannot be controlled except with weed killers which cannot be used between valuable plant specimens. A seasonable cutting with sickle or scythe provides temporary control with the cut tops placed around specimen plants for mulch.
The natural way, as near as possible, seems to be the best way of growing rhododendrons. We believe it better not to fool around with our own inventions, heat in off season and potting, which do more harm than good in the long run. We even had good success sticking rhododendron cuttings in October in our cold pit without heat in boxes covered with a plastic superstructure.
Our plants even with weeds coming up in nursery rows seem to prosper and overcome weed competition in their own natural way. Experience as cited has been made by me in many years of growing plants from seed. We have specimen plants of all sizes up to 14 and 16 feet to show for it.