RHODODENDRONS AND AZALEAS
Growing rhododendrons and azaleas got into my blood in the
early years of training around Dundee’s parks and nurseries. A large drift of
Rhododendron praecox which is one of the earliest to flower was planted in a
bed of pure leafmold in Dawson Park and seemed to thrive. We also had a sunken garden planted with a
range of the dwarf Japanese Kurume azaleas. As a young kid on low wages this
was brilliant as these grew very easy from cutting. Other plants had to be
grafted or sown from seed which then took ages before they flowered.
Azaleas in May |
Then a few years later in Camperdown Park I saw the range
widen to cover flowering from spring till summer. We were blessed with plenty
of experienced gardeners so soon I was taught how to layer some of the large
flowering hybrids, but got moved to another park before my layers had a chance
to root. It was a hard life being an apprentice gardener but very rewarding.
Mixed azaleas |
I have never been without rhododendrons and azaleas ever
since, and a trip to see the massive range growing naturally in the woodlands
around Glendoick nursery is a must at this time of year. They also stock a huge
range of all types for sale and this being one of their specialism’s the
quality is very high.
Rhododendrons and azaleas thrive in a well drained but
moisture retaining woodland acidic soil. They do not tolerate lime in the soil.
They need to be moist at all times so really thrive in the west of Scotland in
areas of high rainfall but provided drainage is good.
They also enjoy dappled sunlight as well as shade and sunny
positions provided it retains moisture.
Rhododendron dauricum |
To encourage good growth and flowering, it is a good idea to
add a light mulch of well rotted leafmold or ericaceous compost in late autumn
or early winter. However they are not heavy feeders so do not give them any
fertiliser as it may scorch the leaves. They do not require any pruning, but it
does help to remove old flower trusses before they start to produce seeds.
Most rhododendrons are evergreen, but azaleas come as both
evergreen and deciduous. Height depends on species and varieties as some may
grow into small trees whereas other are ground hugging dwarfs. Plant hunters over
the last two hundred years have gathered thousands of different species from
all over the world especially China, Tibet, Burma and Japan. Then nurseries and
plant breeders got to work and now we have any amount of different plants to
choose from to suit every situation
Japanese Azalea Hinomayo |
Today many large flowered hybrids are grown as grafted
plants, but can be propagated by layering once the bush is big enough with
branches at ground level, but it is a slow process so patience is needed. The
easiest forms to propagate are the dwarf evergreen azaleas, which can be
layered or rooted from cuttings. Short pieces can be inserted around a shallow
pot with a mixture of ericaceous compost and grit for good drainage. Place a
large polythene bag over the pot to retain a moist atmosphere and rooting will
occur after a few months.
When it comes to selection of the best to grow consider
whether you prefer large bold plants, or ground cover, scent, autumn colour
especially good with deciduous azaleas and how much space is available.
Everyone has their own favourites and as new varieties are coming out all the
time the choice is endless. Rhododendron praecox is a must for me as it is very
early, but then Elizabeth
a low growing bright red was favourite for a long time, but suffers from
mildew.
Potting up sweet corn |
Wee jobs to do this week
Pot up sweet corn
seedlings into their final pots. Grow on for a few more weeks to produce a
strong plant for planting in early June. Plant in square blocks as this helps
with the wind pollination with spacing about 18 inches apart. As planting
occurs later than other crops I take the opportunity to sow the space with a
clover green manure to improve fertility, but it needs digging in at least two
weeks ahead of planting.
END