Many U.K. hardy orchids love growing in alkaline soils above chalk or limestone. So it follows that every hardy orchid and garden meadow lover should consider getting some chalk in, if they don’t already have some. We don’t – our soil is an acidic clay-loam, unfortunately. I have just taken delivery of a build bag from a local quarry and will use it to make some chalky habitats, particularly a raised bed. This is my second bag since we moved here. With the first I made the Chalky Banks adjacent to the Back Meadow. Chalk is also useful, I find, to add a little to the compost when potting up orchids grown from seed.
When we lived in our previous house on the Surrey Downs the soil was similar to what we have now, so I had a pile of chalk dumped there too. Not quite as convenient as in a bag! I am a serial offender when it comes to importing chalk.
There hasn’t actually been a lot of orchid activity in the Chalky Banks yet, but I’m hopeful good things will develop. However there have already been good results from sowing with chalky soils wildflower seed mix. There are flowers of chalk downland that don’t occur on the ordinary mini-meadows: including Lady’s bedstraw, Wild basil, Small scabious, Wild thyme, Common restharrow, and more.
Of particular note is Kidney vetch (Anthyllis vulneraria), which also grew well in the chalky meadow I made in the Surrey garden. In the latter I was delighted on one occasion to find it being visited by a Small blue butterfly (Cupido minimus). There were known wild colonies of these within a few miles of us. It is amazing, though, that they seem able to detect the scent of the food plant from far away.
It all shows what a boon a bag of chalk can be for the garden meadow-maker. Now, what on earth am I going to do with all this left over chalk….
Photos: 1. chalk bag just received, 2. chalk dump at our previous house, 3. Kidney vetch on Chalky Banks, 4. Small blue butterfly on kidney vetch
do you have to mix the chalk with any other soil or do you just move it where you want it?