Repotting cacti

Our daughter has been given 3 cacti (free is also her favourite price), but the pots appear rather small for the height of the plants and they are in what appears to be (loose) peat based MPC. They are all leaning.

What's a cheap DIY potting mix for cacti?


P.S. I have Perlite and there's a big pile of gravel 5 mins walk from home.

 

Hi Scrungee
I know Westland make a specific cacti and succulent potting mix I've not used it so I couldn't say how good it is.

 

I'd be careful potting on at this time of the year, basically they should be going dormant now and approaching their cool dry winter rest period, guessing they are desert cacti.

Best to wait till spring would be my advice, but if you need to sort them out I'd go up only one pot size and pretty much use pure grit, until next year.
Then repot properly next year.

 

Brings back painful memories
Prob at the age of 12 I decided to pot one of my mum's cacti into a very large pot; it was already a large plant......easy peasy I thought. Hold the top in my hand and simply plant it. The pain of thousands of tiny pins in my palm that took months to totally remove left me very wary of cacti. My mum used to grow and sell all sorts of cacti.....should have asked her first
I'm with Pete on this though.....springtime is potting on time

 

'OUCH' plus several expletives. I once had quite a collection of cacti & succulents. I was in the process of planting, displaying the plants on the GH staging set out in landscape form. The plants were on a slatted shelf above the staging. Reaching to select the next one, my hand knocked an Optunia over. First reaction was to catch it. YES just like the slice of bread & jam, it landed face down, tightly gripped in both of my hands. So yes Verdun, like you. I can still feel those spines even now.

Perhaps a tip I can pass on. When repotting or as I prefer, potting on. A piece of newspaper or similar. Say about 12" long, Folded several times so as to form a strap. Gently curve this around the plant and gently pinch the tail ends of the trip/strap together. This will hold the plant, now a slight tap to the pot and the plant comes free. Having previously inserted the pot and plant into the larger pot and having filled in and firmed the compost around the plant, lift out and carry on as mentioned, fill in and gently firm the compost. Plunge in water and let drain.

 

Ha ha, I learned from that experience Mike

 

Opuntias have not only spines but glochids, they are bad tiny spines that are very difficult to remove, I find the best way is to scrape the area with a knife.

The other real bad ones are the fish hook type, ferocactus are good at this, backward facing hooks.
Once hooked the only way out is to rip the thing off.

 

I've foraged some (unused) gravel from a pile left over from tar spray and chipping footpaths and will mix that with equal parts of horticultural sand and JI nr2, both the latter bought ftom end of season clearances, to be mixed in equal amounts. Might seive some gravel for top dressing.

The existing (peat based MPC) soil was soaking wet when my daughter saved them from being disposed of into a green bin. The cacti have been neglected, grown unevenly, and will have the best top 'pads' removed and planted/rooted next year, discarding the tatty lower growth. When's the best time for that? (done it many, many years ago, but forgot best time of year).

Even though it was over 50 years ago that I would help my father repot up to 1.2m (it was 4 foot then) tall cacti, I can recall using different cloths to wrap them with, fine stuff at first that the spines could penetrate, otherwise they would be damaged, and only then something thicker like old towels when the spines were completely protected.

 

Potting compost varies for cacti & succulents, depending upon the natural location and habitat. As a basic mix. Equal parts of washed horticultural sand. Plus the same amount of grit, and the same equal amount of soil/mpc/peat. When repotting, always try and keep as much of the original compost/rootball.
Perhaps your daughter's plants have grown too tall for the tiny pots and/or they have been drawn towards the light. Cacti and succulents have the ability to store water. With our potted up plants, the plants will quickly gather up the amount of water they require, so provision has to be taken into account with the pottting mix. Surplus leftover water needs to be got rid of quickly via good drainage, otherwise the roots will rot and even the base of the plant. An interesting fact I have recently learned. Frequent repotting of cacti & succulents actually is good for the plant. It has been proved that frequent repotting encourages new, stronger growth and promotes flowering. Now it can be seen just why this is the case. Compared to the cultivation of most plants, albeit flowers or veg, these often require a good rich compost etc. Poor old 'Spikey' cactus is expected to survive within the home, in a pot probably having a lesser diameter than the plant and in the poorest of soils.

To all gardeners. Please be aware of 'Roadside cheapies'. Gravel/grit and sand used by road maintenance firms. So often the transportation has been on lorries that have carried all sorts. Petroleum spirit and its derivatives are use d a lot with road repais etc. The freebie grit etc might well be contaminated. Pennywise, pound foolish.

When I was growing lots of fuchsias, there was a world renown grower who one day noticed lots of molehills along the grass verges. Such fine soil. He apparently went out and gatthered up barrow loads. He not only used it for his cuttings but also for potting on etc. He lost the whole damn lot. The local council had been out spraying, this was, brfore sprays were neutralized on contact with the soil.

 

I have to be honest. I have a great passion for books. My beloved wife used to say. Mick,not another book on....whatever.

On the subject of cacti. I have on my shelves. The illustrated guide to Cacti. By Rudolf Slaba published by Chancellor Press. ISBN. 1-85 152-118-6 It was a cheap book but really worth having.

 

I use forceps to hold cacti when I re-pot.

(The ones with the circular ends not the pliers ends type.)

 

I use lengths of folded kitchen roll and as was said above, have the hole ready. Trying to get compost around the base of a prickly plant in a small pot isn't much fun