Rhododendron x praecox
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Rhododendron x praecox is an evergreen shrub that can grow up to 1.50 metres tall.
It has miscellaneous uses.
Although no specific mention of toxicity has been seen for this species, it belongs to a genus where many members have poisonous leaves. The pollen of many if not all species of rhododendrons is also probably toxic, being said to cause intoxication when eaten in large quantities[
A hybrid of garden origin, R. ciliatum x R. dauricum[
Not known in the wild.
Succeeds in acid or neutral soils in sun or part shade. Succeeds in a most humus-rich lime-free soils except those of a dry arid nature or those that are heavy or clayey[
]. Prefers a peaty or well-drained sandy loam[
]. Succeeds in sun or shade, the warmer the climate the more shade a plant requires[
]. A pH between 4.5 and 5.5 is ideal[
Succeeds in a woodland though, because of its surface-rooting habit[
], it does not compete well with surface-rooting trees[
]. Plants need to be kept well weeded, they dislike other plants growing over or into their root system, in particular they grow badly with ground cover plants, herbaceous plants and heathers[
Plants form a root ball and are very tolerant of being transplanted, even when quite large, so long as the root ball is kept intact[
Plants are hardy to about -15°c but the flowers come out in spring and are very frost tender.
Plants in this genus are notably susceptible to honey fungus[
Tolerant of trimming, plants can be grown as a hedge[
Seed - this is a hybrid species and the seed will not breed true. It is best sown in a greenhouse as soon as it is ripe in the autumn and given artificial light. Alternatively sow the seed in a lightly shaded part of the warm greenhouse in late winter or in a cold greenhouse in mid spring. Surface-sow the seed and do not allow the compost to become dry[
]. Pot up the seedlings when they are large enough to handle and grow on in a greenhouse for at least the first winter.
Layering in late July. Takes 15 - 24 months[
Cuttings of half-ripe wood, August in a frame. Difficult[