hi container people. just ordered coir for my containers. do i mix this with any soil and how often will i have to fertilize? will be planting hostas and annuals. also some houseplants. thanks

Hi pitcherell,

Well, I really can’t answer all of your questions, just want to say that I do like using coir. I’ve never used it by itself, only as a small percentage of the growing medium. I add it to all of my seed starting and potting mixes when growing from seed. Coir improves soil drainage and holds moisture very well without getting overly wet. It creates air pockets in the medium that allow excess moisture to drain away from plant roots.

I understand that coir can sometimes contain higher salt concentrations than peat, but I’ve never had problems with that. Commercially available coir has been greatly improved in that regard.

Art

The percentage of coir to potting soil depends on the plant. For example, I have used 1 part coir to 1 part potting soil for my adeniums. For hosta...1 part coir to 2 parts potting soil would be good.

thanks for the info. i will definately mix in some potting soil. i guess fertilize weakly every week!?

Another wonderful thing about coir...it also holds nutrients from fertilizer that you pour onto your media. So 1/4 strength of soluble fertilizer is good, and applied weekly or every 3 to 4 weeks depending on the plant's needs.

I pre-soak coir/wash coir before I use it. I use it with horticultural charcoal for some orchids and epiphyllums that I grow. Coir holds a lot of moisture so got to have good intervals in watering, so be observant of temperature and humidity levels each season.

For the plants that will be outdoors, you can use some time-release pelleted fertilizer to make your life easier. I mix alfalfa pellets into all my outdoor container mix for added slow-release nutrients and microbes, too. The "all natural" potting mixes you see at the stores are a large percentage coir now, too.

Your hostas will love the moisture-retention of the coir, but other annuals might want a mix that dries faster, and for them, I'd mix in some extra Perlite, too. You can get bags of straight Perlite at Lowe's or HD. It's expanded rock so strictly speaking not "natural" but it is perfectly inert and holds air pockets in the soil well, too.