Repotting guide

When & how to repot Moon and Stars Watermelon (Citrullus lanatus 'Moon and Stars')

Also called Moon and Stars watermelon, Cherokee Moon and Stars.

More about moon and stars watermelon

About Moon and Stars Watermelon

Citrullus lanatus 'Moon and Stars' · also called Moon and Stars watermelon, Cherokee Moon and Stars · edible

Moon and Stars is a striking heirloom watermelon (Citrullus lanatus) whose dark rind is dappled with one large yellow 'moon' and many small 'star' speckles, and whose leaves are flecked too. Once nearly lost, it was famously rediscovered in the 1980s. The large, sweet red-fleshed fruit needs full sun, warm soil and a long 90-100 day season.

Mature size: Vines 3-4 m; round to oval fruit commonly 7-18 kg depending on strain.

Watch for — Ripeness judgement: Picked too early they never sweeten; harvest when the ground spot is creamy-yellow and the nearest tendril has dried.

How to tell moon and stars watermelon needs repotting

Repotting on a calendar is less reliable than reading the plant. For moon and stars watermelon, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot moon and stars watermelon on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot moon and stars watermelon

Pot on seedlings as they grow; not a perennial repot. Moon and Stars Watermelonis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Vigorous, long-trailing heirloom annual vine spreading 3-4 m, needing ample room..

What size pot to step moon and stars watermelon up to

Pot moon and stars watermelon on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot moon and stars watermelon

Pot moon and stars watermelon on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting moon and stars watermelon

Pot on before it is root-bound. Check moon and stars watermelon regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh fertile, well-drained sandy loam at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water moon and stars watermelon in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for moon and stars watermelon

Moon and Stars Watermelon wants fertile, well-drained sandy loam. Wants warm, free-draining, organic-rich soil, pH 6.0-6.8. Raised, warmed rows suit its heat-loving roots and improve drainage. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting moon and stars watermelon — frequently asked questions

How often should you repot moon and stars watermelon?

Pot on seedlings as they grow; not a perennial repot for moon and stars watermelon. Moon and Stars Watermelon is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into fertile, well-drained sandy loam so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does moon and stars watermelon need?

When is the best time of year to repot moon and stars watermelon?

Can you put moon and stars watermelon straight into a much bigger pot?

No. Even a fast-growing moon and stars watermelon should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise moon and stars watermelon after repotting?

Not immediately. Wait about 1 week after repotting moon and stars watermelon. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.