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Depth rule: 2-3x the bulb's own height, pointy end up. Drifts beat rows: scatter by hand and plant where they land. Tulips wait for November (cold soil dodges tulip fire disease); everything else goes in September-October while the soil's warm. Buy by the sack, not the net of 10: bulk pricing is a different hobby.
What The Bulb Planting Calculator Works Out
- Bulbs needed: planting area x the display density for the bulb: tulips 50 per m2 for the solid municipal blaze, daffodils 40, crocus carpets at 100, alliums punctuate at 15, snowdrops 75. Even a modest 2m2 border swallows a hundred tulips.
- Planting: the depth and month for each bulb. Depth is two to three times the bulb's own height, pointy end up; too-shallow planting is why first-year triumphs vanish by year two. Tulips wait for November's cold soil to dodge tulip fire; everything else goes in during September-October.
- The rule of three: bulbs naturalised in lawn go in at half density for a natural look, and the grass must not be mown for six weeks after flowering while the foliage feeds next year's bulb.
- Custom density and planting style (advanced): type your own bulbs per m2 or switch between border (full), lawn (half) and container or bulb-lasagne (1.5x, packed shoulder to shoulder) planting. A lasagne pot stacks crocus over tulips over daffodils for months of bloom.
- Spare for losses (advanced): adds a percentage for squirrels, rot and the odd dud. 10% is sensible for tulips in a squirrel garden; chicken-wire lids until shoots show are the other defence.
- Spacing (advanced): the grid spacing that gives your density (the square root of 10,000 divided by bulbs per m2), as a sanity check when planting drifts by eye.
- Packs to buy and cost (advanced): packs at your chosen size and price, with cost per bulb and per square metre. Garden-centre nets of ten run 40p to GBP 1 a bulb; wholesale sacks 10p to 25p, which is why September's catalogue order funds April's display at a fraction of the impulse-aisle rate.
- Planting time (advanced): hours at about 100 bulbs an hour with a trowel, 200 with a long-handled planter or 300 with a drill auger, with a suggestion to split big plantings into sessions.
- All-bulbs table (advanced): the count, packs and cost for each of the five bulbs over the same area, so a mixed scheme can be ordered in one go. Daffodils, crocus, snowdrops and most alliums naturalise and compound; big showy tulips mostly dwindle after their debut, so the cutting-garden school treats them as annuals.