inherited a garden full of rhododendrons. They all flowered wonderfully
this year, but I don't know what to do now. Should I break off all
the old flowers? And do rhodos need any special fertiliser?
off the old flowers to prevent seed pods forming and to encourage
the plant to put energy into new growth which will carry next spring's
flowers. You can prune rhododendrons now too, if they're getting
big. Old plants can be pruned back severely and will soon regrow.
Otherwise just remove any dead or damaged shoots and shape the plant
don't need a lot of fertiliser but if they look hungry (pale leaves,
perhaps even yellowing leaves, and not much fresh growth) you can
feed in spring with a blend specially formulated for acid-loving
plants - often sold as azalea, camellia or rhododendron fertiliser.
Rhododendrons have very
fine roots that grow close to the soil surface, so they appreciate
a mulch of acidic, organic matter like peat or fine bark which keeps
the root system cool and conserves soil moisture through the heat
of summer. A layer of mulch, 6-8cm deep over the root system (avoid
contact with the trunk) can have a greater beneficial effect than
an application of fertiliser - but there's no harm in doing both
for an extra boost. Make sure to follow the recommended application
rate on the fertiliser bag, those fine roots can be damaged if you
overdo it. And water the fertiliser in well if it doesn't rain much
for the following few days.
Gardener, Issue 136, 2003, Page 35
Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.