Redwood soil conditioner?
OSH brand?

Is this a California thing, like Happy Cows?

Please explain.

matermark

Sunland Redwood Soil Conditioner appears to be basically composted wood chips and bark fines. If this is the case, then yes, you'd have to add fertilizer to what you are describing as basically a soilless growing medium.

Your addition of fertilizer can be in the form of time released granules, periodic and regular liquid applications, or a combination.

sonaliagrawal - I'm not sure but I think this is one of those custom recipe mixes they talk about over on the Container Gardening forum, right?

Since your question is about the mix itself, the best place to to ask about it would be on that forum where the folks who actually use it could help you.

As a general rule, yes, as penny already said, you do have to add fertilizers to home-made mixes.

Dave

Hi sonaliagrawal-

I am using this mix as well. The recommendation is to fertilize weakly, weekly. I believe at about 1/3 - 1/4 strength fertilizer. There is a thread in the container forum specifically about fertilizing in this mix.

There is A LOT of discussion about organic vs non organic fertilizing in containers, so you'll have to read up and decide what is right for you. The amount above references using a fertilizer such as MG.

I just put a post up about trying to get better in-ground tomato plants, as all of my plants in this mix in containers are doing very well, and my in-ground plants aren't nearly as happy.

Oh, and don't forget to add the dolomitic lime!! :o) Check the recipe to get an idea of what is appropriate for your container size and volume of mix. I ended up with about 8 Tbsp. per container, and I have 15 gallon containers. (not 18 gallons...made a mistake in my other post)

If justaguy is around in this forum, I believe that he grows tomatoes in this mix and may be able to comment on it.

Good luck!!

Here is a link that might be useful: Fertilization thread re: container plants

You have to be careful about the wood. If you are using pine/fir bark you are fine. If you are using part bark, part sapwood you may be looking at a nitrogen immobilization problem as the sapwood ties up N as it breaks down. The reason for using pine bark as the basis of a mix is that is breaks down very slowly (much slower than peat). By using sapwood, the slow decomp is negated and N immobilization can/likely will occur.

In any event, fertilizer is absolutely required in containers as the mix has no real store of nutrients to sustain the plants.

Normally a fertilizer in a 3:1:3 ratio would be good, but if your mix contains sapwood you might choose 3:1:2 instead such as Miracle Grow 24-8-16 to try to offset the N immobilization from the sapwood. It's a bit of a guessing game if your mix contains sapwood as the N tied up by the decomp of the sapwood will be released at some point.