Watering Cacti Seedlings and Humidity

by Oliver Even
(Hayward, WI, USA)

Photo is of a 10.5 by 21 inch black rectangle greenhouse box

Hello, I recently bought a "Cacti Mix" pack of seeds and just put them into a 10.5 by 21 inch seed starter pan that's about 2.5 inches deep, it also has a clear lid, I'll leave a photo of one that looks identical.

The lid doesn't clasp shut completely, it just sits, I use them for my other veggies and flowers and it does keep the humidity in.

Anyways, I've seen that you're supposed to put saran wrap over the pot or put the whole pot in a Ziploc, what should I do with what I have mine in? And how/when do you water the seeds if they're supposed to be covered?

Comments for Watering Cacti Seedlings and Humidity

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May 23, 2020

Not Necessary
by: Jacki Cammidge, Certified Horticulturist

Propagating cactus seeds is a whole different thing than most vegetables.

Think about it. They've evolved to live in warm dry climates (like deserts) so they have developed certain traits, like not needing much water.

The thing with plastic domes is that the water tends to condense on the top of it, then run down. This creates the wrong conditions for cacti.

Saran wrap is the wrong thing too. No need for that.

In nature, in their natural habitat, the seeds of a cactus plant would fall down to the soil below the adult plant.

This creates a tiny bit of shade in the harsh sun of the desert. This is why you commonly see clusters or colonies of cactus plants.

The baby plants survive by being in the shelter of the larger plants, which also repel moisture (like daily dew) which will run down the adult cactus into the soil.

Get the picture?

This means that the air is dry, but there's a tiny amount, daily, of moisture on the surface of the soil. Do not drench these plants, at any stage.

Lightly sprinkle or spray the soil near the seedlings when they emerge, while periodically letting them dry out a bit. They'll need bright light, but not full sun until they're older.

Typically, the seeds would drop at a time when there are showers happening, or heavy dew at night time. Copy that, and your cactus seedlings will be happy.

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