Fruit Seeds: 13 Kinds to Sow, From Melon to Alpine Strawberry

Picture it: mid March, a bright windowsill, a cheap propagator, and a balcony or bed that gets sun from lunchtime on. That's the whole setup for most of this shelf. If you grow one thing off this page, make it Watermelon 'Crimson Sweet' (Citrullus lanatus) Seeds, though watermelons can be fiddly the first year you try them.

Start Them Inside While It's Still Cold Out

Almost everything here starts in trays or small pots indoors or in a greenhouse, not in cold soil. Citrullus lanatus 'Crimson Sweet' goes under glass in March or April, Bitter Gourd (Momordica charantia) Seeds get about four weeks inside before moving out for summer, and Ground Cherry (Physalis peruviana) Seeds want an indoor start in early spring and a move outside in early summer.

Greenhouse and indoor starts

Sow from February to May in a heated mini greenhouse or a propagator on your brightest windowsill. Coco or peat pots of free draining seed compost keep it simple: one or two seeds each, lid vented so the surface never turns swampy.

Soaking and pre-treatment

A few hours in lukewarm water softens the harder cucurbit seed coats and speeds things up. Species that want a cold spell can sit two weeks in damp substrate in the fridge, then go somewhere warm.

Heat Does More Than Fertiliser Ever Will

Grandian Strawberry F1 (Fragaria x ananassa) wants a protected seedbed at around 20°C before it sees open ground. Kiwi (Actinidia deliciosa) is stranger: a damp paper towel in a clear ziplock bag kept somewhere warm sprouts in roughly two weeks, then into small pots of slightly acidic soil. Kiwano (Cucumis metuliferus) Seeds need the same warm start, greenhouse first and full sun after, for a spiky fruit that tastes somewhere between lemon and banana.

Temperature, light and humidity

Around 20 to 25 degrees suits germination across this shelf, and the brighter the spot, the sturdier the seedlings. Keep the cover on until shoots appear, then open it a little wider each day to bring the humidity down.

Potting on and hardening off

Prick the seedlings out into their own small pots at a couple of real leaves, holding them by a leaf rather than the stem. Ten days of daytime trips outside, back in at night, hardens them off before planting out after the last frost.

Pots on the Balcony or a Bed in Full Sun

Alpine Strawberry (Fragaria vesca), in red or Yellow Cream, stays small and suits a pot or a window box. Melon pear (Solanum muricatum) is a shrub, so give it a big container of rich soil at a neutral pH. Kiwi is a vine and needs wires or a frame to climb.

Open garden and raised beds

Melons sprawl, so they want open ground, a raised bed or a very large pot. Sow Muskmelon 'Oranje Ananas' (Cucumis melo) Seeds outdoors after the last frost, 30cm apart, a few seeds per spot, then thin. Work in compost and keep drainage sharp.

Melons in a Closed Greenhouse Need Your Help

No insects inside means no fruit, so move pollen from the male flowers to the female ones with a soft brush in the morning. Same job for Cucumis melo 'Charentais', 'Oranje Ananas' and Crimson Sweet, while plants outside get insect pollination for free. A ripe muskmelon smells aromatic before it looks ready, so trust your nose over the calendar. If that sounds like too much, Lemon Apple Cucumber (Cucumis sativus) Seeds are far less needy under glass.

One Summer, or Six Years

Melons, cucumber, kiwano, bitter gourd (ready around October), ground cherry and melon pear all go from seed to fruit in one season. Kiwi does not: from seed it bears fruit after four to six years, the one plant here that asks for real patience. Strawberries take their time too, and Grandian F1 is worth resowing every year. Kiwi and strawberry are the only perennials on this shelf, so if you came looking for fruit tree seeds, this isn't that page.

Sowing and harvest at a glance

Sow under glass from February to May, harden off, plant out after the frosts, then pick from midsummer into October depending on the species. The Fruit Seed Pack from Zammi's Farm holds Crimson Sweet, kiwi, Grandian F1, alpine strawberry, ground cherry, kiwano and melon pear in one go. Keep leftover seed cool, dark and dry, and check the germination rate and packing date before next spring.