Thanks for posting your experience. Your begonias look really good. I also bought a bag last year from costco and had a similar experience to yours. When I lived in Watsonville I used to buy from Antonelli regularly and was always pleased. I bought two bags from Costco this year because they were a different species and I think the flower will be better and the plant growth more restrained. Al

I realized after I posted the pictures that the begonia picture perfectly portrays my experience. I got the tubers all mixed up so the red Knock-out begonia is in the pot with a yellow orange one. Look closely, behind the red one is an Ugly one that I broke off! This year I am starting them in labled cups.

Somebody told me to put some manure way down in the pot mixed with sand and perlite for when the plants get big. It worked great! Best begonia year I ever had. I got the Camellia bug and so I filled up my spaces for begonias but aren't they spectacular?

Thanks kitty, good idea. I bought some Kellogg outdoor potting soil and it smells like it's going to be good stuff. I also bought a bag of chicken poop. I had planned to top dress around the garden but had not considered adding to the bottom of pots, I have a zillion. I have seen what chicken poo does to pasture land, deep green. It's strong stuff and I will be careful.

I would be concerned that adding manure to pots would have an adverse effect on the pots drainage which could cause rotting of the roots. Al

I would use the bagged Miracle Grow potting mix for begonias. It's light and fluffy.

I have the composted bag chicken manure. What is your thinking, too fine a texture? I thought I would have to use it sparingly anyway or might get too much foliage. Potting soil in general I don't feel I have gotten under control. I made the mistake of using Costco Miracle Gro moisture plus last year. When it's wet it feels like ground cardboard. It never dries out but works great for impatiens. I have a drip system and of course pots on a system have a mixture of sunny and shady exposures. Dry loving plants in the shade never dried out. This winter I tried putting together Al's mix, 1-1-5 and already I can see it drains too fast, if I even got it right. I am trying Kellogg brand now. I add 15% Turface because I don't like perlite. The extreme summer temperature in the valley are a challenge. I use Osmocote but organic gardeners think fertilizer salts kill the soil microbes. What do you plant your begonias in Al?

I buy #1 nursery mix from Wheeler Zameroni landscape supply on Petaluma road. It contains forest products(ground up bark)builders sand, pumice rock and a fertilizer package that ends up with a PH of about 6 1/2 . In my pots I add a teaspoon 18-6-12 timed release fertilizer from Purity Products per gallon of mix. With a potting soil entirely without soil I do not use compost or try and build the soil microbes or nutrients as I do in the garden. I do not use any mix in containers that contain peat because it turns to a goo very soon that does not drain when wet and when dry it shrinks and will not absorb water. Al

Al, does Wheeler Zameroni manufacture the #1 nursery mix? Is it in a bag or do you buy this in bulk? My last years potting soil contains a lot of coconut fiber (coir) I believe. I would not say it goes to goo! I used some of the old stuff to fill in and level under some brick yesterday. When I stepped on the bricks today they were resilient despite the potting soils amazing compacting abilities. I think hypertufa might be the most suitable use for last years potting soil.

I buy the nursery mix by the yard, about $45. You can buy as little as one cubic foot and they supply the plastic bag. They make it them self as at least 6 other landscape supplies here in northern California do also. Wheelers has 10 mixes made for specialty commercial nurseries. The number one mix is the most commonly used one. In any mix it is the organic portion that breaks down, in this case the fir bark is the longest lasting organic available. You can ask for the spec sheets on the mixes available and look at the contents of each one. If you are going to keep your plants in a container for more than 2 years the container will usually be pot bound and need a soil change and either a division or a potting up. For a longer time in the same soil I think the gritty mix is worth the extra cost. Al