Brian answers readers’ horticultural queries
Can you tell me the difference between sharp sand, potting sand, silver sand and building sand and can building sand be used to help break up clay? HF, Waterlooville. Sharp sand has fine grains but the bulk of the material is sharp and gritty. Potting sand also has fine grains, but the larger pieces are rounded. Silver sand is a light grey colour and is very fine. It falls through the fingers when dry. It’s a bit like the sand in an egg timer. Builders’ sand contains some clay particles and can be used to help break up clay soils as long as it is scattered on top of rough dug ground during the autumn.
What is the name of the plant which collapses when the leaves are touched but becomes upright after a period of time and can it be grown from seed? JD, Denmead.
This is the sensitive plant, botanical name mimosa pudica (pictured). You’ll find the seeds in catalogues. A wonderful plant if there are children in your life.
I had a pretty climbing annual pot plant about 10 years ago when I was a boy. It had flowers like busy Lizzies, but the flowers were a distinct orange with a brown centre. Do you know what the name could be and where might I buy one? DG, Anchorage Park.
It is called brown-eyed Susy (thunbergia)and you’ll find it in stock at Keydell Nurseries, Horndean. I agree with you, it is a pretty annual climber.
JOBS FOR THE WEEK
Sow another batch of dwarf French beans. Be prepared to cover them with cloches in September and they will provide beans right up until the cold weather arrives in late autumn.
Feed indoor cucumbers twice a week with a high nitrogen liquid feed. This will encourage rapid growth and more little cucumbers will form in mid-August. If white patches are appearing on the leaves, apply a thick dusting of sulphur powder which will prevent the powdery mildew from spreading.
Sow large-rooted radish for winter stews. Simply sow them in a drill outdoors.
Trim off the dead flowers on sun roses – helianthemum. This will encourage new growth which will produce masses of blooms next summer.
Sow short rows of Autumn King 2 carrots. These can be left in the ground for digging during the winter. Cover the row with insect barrier mesh (Keydell Nurseries stocks it near the fish food) suspended by half circles of plastic water piping to keep the carrot root fly away from the seedlings.