At this time of year, potatoes can be earthed up easily when
the soil has been softened by rain. Potatoes can be grown
successfully without this step, but hoeing the soil from
between rows on to the bases of the plants prevents the
tubers being exposed to air and turning green.
Green potatoes have high concentrations of a glycoalkaloid
poison, solanine, and should never be eaten.
Mounding up should be done before the plant tops are too
large and likely to be damaged during the process.
Main-crop potatoes such as Red Rascal, Heather and Agria can
be planted and good crops should be produced in soils that
retain moisture through to late summer.
Onions sown now will not grow to full size, but will produce
bulbs large enough for pickling. Make the ground rich and
firm and sow in shallow drills.
Autumn-sown onions should be growing well and will be helped
by an occasional watering with liquid manure and a
top-dressing of sulphate of potash.
Runner beans live up to their name and growth should now be
rapid. If not planted against a fence or trellis, or on a
bean tepee, they will have to be staked.
Put tall (2m) sticks on either side of the row and tie string
along about halfway up and also near the top. Earthing up on
either side of the plants helps them stay in place in windy
Keep the roots moist and cool with plenty of water.
Lawn clippings can be used as a mulch but make each layer
thin (1cm) as otherwise too much heat will be generated.
Peas can be staked but growing against netting is more
effective for tall varieties. Staple netting to several tall,
strong stakes, leaving the lower 40cm or 50cm below the
netting. This makes a movable fence that can be used for peas
year after year.
As the first tiny broad bean pods appear, the tip of each
stem can be nipped out to help give a better crop. The green
tips of the plants can be eaten in stir-fries.
Rhubarb plants will weaken if too many stems are picked at
once, so take no more than a third of the leaves at any time.
Rhubarb likes cool roots and is a greedy plant, a gross
feeder in gardening jargon, so keep it well watered in dry
weather, and work some compost around the base before
Removing dead heads from rhododendrons and azaleas will pay
dividends with better displays next spring.
Sweet peas sown now will bloom late in the season. In
general, heritage varieties have better perfume but smaller
Sweet-pea seed can be sown in rich soil, then seedlings
thinned to 10cm-12cm apart. Less wasteful is to sow them in
seed boxes and plant out when the first pair of true leaves
Keep plants watered or they will produce small, miserable
flowers on short stems.
Primulas, polyanthus, primroses and auriculas should be
divided as soon as the plants have finished flowering.
Prepare ground for them by adding rotted horse or cow manure
or compost. If the soil is heavy clay, add coarse river sand
to help it drain. The plants like to be firmly fixed in the
soil with the lower leaves just above the surface. Old plants
tend to lift out of the soil and will fail to flower freely
if left undivided too long.
Wallflowers (Cheiranthus) are old-fashioned flowers with a
distinctive sweet fragrance. Seed sown now should give
spring-flowering plants. They keep going for years if
deadheaded during the flowering season and cut back by half
Like most spring-blooming shrubs, lilacs can be pruned when
flowering has finished. A mulch of decayed manure, mixed with
some garden lime, will improve lilacs. Wisteria can also be