What to Grow
The short answer
Growing guides for 12 crops under glass. Leafy greens are the right first crop in any unheated or lightly heated greenhouse: most tolerate frost, several improve after one, and they do not need the hand pollination that fruiting crops do.
12 pages in this section · researched from published specifications and verified owner reviews
Fruiting crops
1 pages
Higher reward and much fussier. These need warmth, light and usually hand pollination, since there is no wind or insect traffic inside.
More crops
11 pages
Everything else covered so far.
- Lettuce Greenhouse lettuce temperature, DLI, spacing, succession intervals and the bolting and tipburn failures specific to growing under cover, with the numbers rather than the adjectives.
- Spinach Greenhouse spinach temperature, DLI, spacing, the day-length trigger behind bolting and why cold weather noticeably improves the flavour, with the numbers rather than the adjectives.
- Kale Greenhouse kale temperature, DLI, spacing, why cold improves it, and the aphid and whitefly pressure that a closed structure creates for brassicas specifically.
- Microgreens Greenhouse microgreens seeding density, blackout period, light, watering from below and the damping off problem that dense sowing creates, with the numbers rather than the adjectives.
- Carrots Greenhouse carrot bed depth, soil texture, germination moisture, spacing and the forking and splitting failures that come from stones, fresh manure and irregular watering.
- Basil Greenhouse basil temperature, light, pinching technique, succession timing and the downy mildew and cold damage that end most basil crops early.
- Orchids Greenhouse orchid light levels, the night temperature drop that triggers flowering, humidity and airflow together, and why bark rather than compost is what keeps epiphytic roots alive.
- Geraniums Greenhouse pelargonium temperature, light, the overwintering routine that keeps plants year after year, taking cuttings, and the blackleg and botrytis failures that come from wet winter medium.
- Tomatoes Greenhouse tomato temperature, DLI, spacing, string training, pollination and the specific failures under cover, with the numbers rather than the adjectives.
- Peppers Greenhouse pepper germination temperature, DLI target, spacing, support, pollination and the slow-start problem, with researched figures rather than generalities.
- Cucumbers Greenhouse cucumber temperature, DLI, vertical training, the parthenocarpic variety question, watering and the bitter fruit problem, with researched figures.