Quick Qu estions
What’s wrong with my po ed rhodo?
Sue Collins, by email The likely cause, as you feel you’re watering enough, is a wide diurnal range in temperature with sunny, hot daytime temperatures but noticeably chilly nights. Plants will grow out of the problem as we go through the summer. But I wouldn’t totally rule out underwatering, as po ed shrubs can need watering three or four times a week in warm spells.
Why do the different varieties of sisyrinchium open their flowers at different times of day?
Bob Wilkinson, Norfolk The so-called blue-eyed grasses are charming flowering plants of the iris family, ideal for gravel gardens and troughs. There are some 200 species in North America and flower opening appears to depend on where they originate. Those bred from
S. brachypus, from
Where can I get the purple-podded pea ‘Blauwschokker’?
Garry O’Sullivan, Hillingdon, Middlesex This garden pea’s worth growing as an ornamental plant in the flower bed. Seed is available from Su ons (tel: 0844 326 2200) and Tamar Organics (tel: 01579 371 098).
Will cement waste contaminate my soil?
John Collins, Surrey The washings from trowels and buckets contain lime, which is alkaline. It’s certainly not good around ericaceous plants, such as rhododendrons, but elsewhere I’d not be too worried. Scrape up any contaminated soil and pour over a few buckets of water. Once dry, fork over the area. California, flflower early in the day, while those bred from S. angustifolium, from Eastern USA, flflower later in the day. Why though is a mystery to me!