Gadenin日本語Get the appGet the ground right before you open the packet
The name is the instruction. Gypsophila means gypsum loving, and the plant comes from open chalk and limestone country where the soil is thin, stony, alkaline and bone dry by midsummer. Sow it into rich, damp, acid ground and it germinates perfectly well, grows for a few weeks and then rots at the collar. Almost every failure people blame on bad seed is really a soil failure that showed up later.
Aim for a pH of 7.0 to 7.5. On neutral ground, work a couple of handfuls of garden lime per square yard into the top few inches a month before sowing and water it in. On genuinely acid ground, lime alone will not hold; build a raised pocket instead, mixing the native soil half and half with coarse grit and adding lime to that.
Drainage matters as much as the lime, and the two are usually fixed by the same action. Fork in a bucket of horticultural grit or sharp sand per square yard, and avoid compost and manure entirely. Rich ground gives soft leafy growth, few flowers and a plant that goes over in the first wet spell. A slight ridge or a raised bed is worth building on heavy clay, because gypsophila will not survive a winter with its crown sitting in water.
| Soil condition | What happens to the plant | What to do before sowing |
|---|---|---|
| Limy, gritty, free draining | Grows steadily and flowers heavily | Nothing; sow straight into it |
| Neutral loam | Grows well but shorter lived | Lime a month ahead, fork in grit |
| Acid and moisture retentive | Dies at the collar within weeks | Build a raised, limed, gritty pocket |
| Recently manured or composted | All leaf, few flowers, floppy stems | Sow somewhere else this season |
| Heavy clay that stays wet | Winter losses of perennial plants | Raise the bed or ridge the row |
Sow a quarter inch deep into warm soil
The seed is small, hard and dark, roughly the size of a pinhead. Cover it about a quarter inch (6 mm) and no more. Deeper than half an inch (12 mm) and a good share of seedlings run out of reserves before they reach the surface, which is why a heavily raked and trodden seedbed often comes up patchy for no visible reason.
Germination is quick once the soil is above 60F (15C), usually seven to ten days, and faster at 70F (21C). Sown into cold wet ground in early spring the seed simply sits, and much of it rots. There is nothing to gain by sowing before the soil has genuinely warmed, because gypsophila grows fast enough to catch up.
Sow direct wherever you can. Both the annual and the perennial resent root disturbance, and the perennial in particular starts driving a taproot down within days of germinating. If you must raise plants under cover, use deep cells or root trainers rather than shallow trays, sow two seeds per cell, and plant out while the plants are still small, before the taproot reaches the bottom.
- Rake to a fine, firm, stony surface Break the top inch down to a crumb, then firm it with the back of the rake. Leave the grit and small stones on the surface rather than picking them off; they keep the crown dry, which is exactly what this plant wants.
- Draw a shallow drill and water it first Make the drill a quarter inch deep, water along the bottom of it and let the water soak away before sowing. That way you can leave the seedbed alone afterwards instead of washing fine seed about with a can.
- Sow thinly and cover with dry soil Aim for a seed every inch (2.5 cm). Draw dry soil over the drill with the side of your hand and firm it with the flat of your palm, not with your foot.
- Do not mulch the row A damp mulch against the seedling stems is how young gypsophila rots. Bare limy soil, or fine grit, is the right surface.
The annual is sown in succession; the perennial is sown once
These are two different plants that happen to share a name, and confusing them wastes a season. The annual kind is a fine, wiry, quick plant that goes from sowing to full flower in about eight weeks and is finished five or six weeks later. The perennial kind takes most of its first year building a taproot and a woody crown, flowers modestly at the end of that year or not at all, and then comes back bigger every spring for years.
Because the annual is over so fast, one sowing gives you a fortnight or so of usable flower and then a bed of brown wire. Sow a short row every three weeks from the point the soil warms until midsummer, and you will have flowers continuously until frost. This is the single most useful thing to know about growing gypsophila for cutting, and almost nobody does it.
Sow the perennial once, in its final position, and be certain about that position before you start. It makes a fleshy taproot that will not tolerate being lifted, and a three year old plant cannot be moved successfully. Give each one two to three feet (60 to 90 cm) of space; a mature plant makes a cloud three feet wide and will smother anything sown closer.
| Type | Sowing to flower | How long it flowers | Sowing plan |
|---|---|---|---|
| Annual | About 8 weeks | 4 to 6 weeks, then done | A short row every 3 weeks until midsummer |
| Perennial | First full flush in year two | 6 to 8 weeks each summer, longer if cut | Once, in its permanent place |
| Perennial, autumn sown | Flowers the following summer | As above | Sow in early autumn where winters are mild |
| Either, under cover | 2 weeks earlier at best | Unchanged | Deep cells only, planted out small |
Sowing the annual and the perennial in the same row is a common mistake and it always ends with the annual being pulled out over the top of the perennial's crown in autumn. Keep them in separate rows and label both.
Thin ruthlessly and never transplant the thinnings
Thin the annual to six to nine inches (15 to 23 cm) apart as soon as the seedlings have two or three true leaves, and the perennial to its full two to three feet (60 to 90 cm). Crowded gypsophila draws up thin and weak, then flops as one mat at the first rain, and unlike many annuals it does not recover its shape once flattened.
Snip the surplus off at soil level with scissors rather than pulling them. The seedlings root deeply and quickly and pulling one lifts its neighbor. There is no point saving thinnings: a gypsophila seedling whose taproot has been broken makes a stunted, short lived plant even if it survives the move, so composting them is the honest choice.
Thin in two passes a week apart if slugs are about, so you have spares in hand. Once the plants have a firm woody base they are of very little interest to anything, but the first fortnight after germination is when a row disappears overnight.
Write down the sowing date, the date the row came up and the date of the first open flower for each succession sowing. Two seasons of that gives you the exact interval your own conditions need between sowings, which no packet can tell you.