h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've got a little cactus, about 3 inches high.

The instructions say:

Keep moist during spring and summer. No water over winter.

Just what are the spring and summer months to a cactus? And how moist is moist?

I've never had one before so I'm a bit concerned with getting it right.

Normally around March to October.
If it flowers, feed it.
Moist is so that the soil feels slightly damp, but there should not be enough water to collect in the drip tray.
Cacti are very easy to look after; if you don't follow the instructions it will probably survive, it just won't grow as well and won't flower.

Indeed. The trick to plants like this is more to do with drainage than amount of water poured on. The 'soil' it's in should have bits of rock chips in - or something like so that the water runs through more easily. If ever the cactus gets overdry - or indeed after the winter - you may find that the soil won't take up water - it just runs right through. Try adding a *tiny* drop of washing-up liquid to the first water of the spring.

Ready to water went the surface of the soil feels *just* dry to the touch.

And the easy way to remember the spring/winter thing? Change your plantcare regime when the clocks change - easy!

"Just what are the spring and summer months to a cactus? "

It isn't what's spring and summer to the cactus (it can't read) but to you. Your spring and summer will start and stop at different times, depending on where you are in the world.

Depends entirely on where you live Spinks. I'm assuming you're in the UK, so most cacti would start to wake up around April and be ready to go dormant again around September, but of course it's never that simple is it

If you see flower buds appearing at any time, then start watering - a little at a time at first. The biggest thing to remember is not to let to the roots sit in moist soil for too long - the soil must dry out between waterings.

I had a greenhouse full of cacti when I was at school in London, and during the summer I'd give them a good soaking once a week by standing the pots in a tray of water until the soil was saturated, then leaving them alone until the following week. I always did it on the same day so I'd know when to water them and when not to. Now I'm living in Texas I use the same procedure, but the growing seaon is rather longer.

If they're in the same pot you bought them in, chances are that they're already in well drained, cactus friendly soil. If you want to repot them, cactus soil is pretty easy to find at most garden centres. Just remember to get a pot which has drainage holes at the bottom so the water can get out, try not disturb the root ball too much, and *don't* water it for a few weeks afterwards - cacti are very susceptible to rot from root damage. Some people say that you should only repot a cactus at the beginning of the growing season, but that's only for the purists.

Do you have any idea which cacti you have - did any of them come with nametags?

Don't know why I kept saying 'them' when you said you have one

However, I do feel a new Guide entry coming on

It's a Euphorbia enopla!

http://studwww.rug.ac.be/~pcolpaer/fotos/Euphorbia_enopla.jpg


I'd searched for it on the net in vain. I never realised there are so many different types of cactii. Today I was finally in the garden centre where I purchased it and looked at the name tags.

It's a toughie. It got blown off the shelf and broke one of its 'arms' but this doesn't seem to have had an adverse effect on it.

Be careful of the milky sap which comes out of Euphorbias - in some species it's toxic

The milky sap was the first thing I noticed on the floor before I saw the maimed cactus. I would've thought it would be full of something watery.

Most cacti are. However, Euphorbias aren't cacti - they're succulents. All cacti are succulents, but not all succulents are cacti

I have two San Pedro cacti. One appears to be fine whilst is developing whta appear to be white scars on the flesh. There's still good growth to it but I am a little concerned. Can anyone assist?

Er, are you just using them as ornaments, or for anything more mind-bending? Is it possible anyone is aware of the traditional uses the people of the Andes had for this type of cactus? If so, they might be cutting it to get at the stuff in the middle!