Grit, perlite or vermiculite.

I find that multi purpose, on its own, tends to compact, and that then restricts the air that gets into the compost.

For things like Tomatoes, being raised in the spring, the plants are potted on so quickly, and the plants grow so fast, that it makes little difference.

But for things that grow more slowly the compost is often like a brick when I pot on.

So I now add 10% perlite, and I find that the compost remains fluffy.

Not tried sand, so can't say how that might compare, but it would certainly improve drainage (but I don't know if the compost would stay "fluffy" which is what I want - I want plenty of air to continue to get into the compost)

For cuttings, and things that are prone to rot if they get too wet, I increase to 50:50 multi purpose and Perlite.

(For me I would prefer to buy separately and mix them)

 

The main reason I never used Perlite was simply that you rarely saw it in garden centres and then it was always in small bags and expensive.

However I have since found 80 (or 100) litre bags of both perlite and vermiculite at Gordon Riggs http://www.gordonrigg-gardencentres.co.uk/ for £16. So I have a bag of each - but still tend to use sharp sand as old habits persist.

 

No stores in my area

 

They take online orders, Pam and delivery is to mainland UK. However, looking at the delivery charges, it possibly isn't worth your while.

 

Another lover of Perlite!! Excellent stuff.

Val

 

One extra thing you can use Perlite for is, Put it in your cavities to insulate the home.
It has reduced my outgoings in this area by the cost of the bags I put in for one year thus far.

I also use it to mix up my seed and potting compost too.

 

Are you sure this is Perlite?

Val

 

I thought Vermiculite was used for cavity insulation, but it wouldn't surprise me if Perlite would work as well. Provide the material itself is an insulator its trapping of the air (so no convection currents can "flow") would be a large part of its job.

Best to get some professional advice, and use the right material though, as its a long term thing, and if you get damp or cold-bridging I reckon you could be worse off than no cavity fill at all.

 

I always mix some perlite into the compost with a little horticultural sand but not to much else the soil will not retain much if any water! As weird as it sounds, when I sow Spring Onion:White Lisbon I do not cover the seed with compost but instead only cover them with perlite! Strange I know but don't seem to have much luck when I cover them particular seeds with compost, all my other seeds grow fantastically covered with soil!

 

I also have a question regarding this topic. As i am specializing in growing chilies this year, i have been told by a lot of people to add purlite to the compost i am going to sow my seeds in, and to sprinkle vermiculite on the top. However, i have not got a clue on what ratio to use. Could someone please help me with this?

Thanks,
Dale Weatherby.

 

I place the seeds on the surface (seeds which are the size of peppercorns I gently push into the compost using the rubber on the end of a pencil, or the blunt end of an ordinary pencil), and then I "drizzle" Vermiculite on top. That only just covers the seeds. I then put the seed tray / pot in a plastic bag (or a propagator with a clear plastic dome/lid) until it germinates so that I don't need to water it again - i.e. any evaporation will condense and run back into the tray / pot.

This is just generic information, some seeds need to be buried deeper, some need light [although vermiculite is sufficiently transparent that that is normally OK for them too], and some need a period of severe cold before germinated etc etc.

In general I add 10%, by volume, of Perlite to my Multi Purpose Compost for potting on things.

Dunno about compost for sowing seeds as I only ever use John Innes Seed Compost, which is soil-based, very sandy / free draining, and certainly doesn't need anything like Perlite adding.

For Cuttings I add up to 50% perlite, to make a very free draining mixture. That would probably be OK for seeds, but they will need watering more often (once they are out of the plastic bag / propagator), but as I said I don;t use Multi Purpose for seeds, so you'd be better to wait for someone else's advice on that specific point

 

Think you'll need the grit for your paths, guys