Q. My last load of mushroom compost with chicken poop had redwood chips in the load. The guy who delivered it didn't clean his truck bed before hauling over my load of compost. So, I've no idea if this contributed to the smaller garlic bulbs OR if i did something wrong OR if was the early 90 degree weather W/ the cold/freeze snap we had 4 times this spring. Spacing was 4"/6" apart in a triangle grid; the other bed was 6"/6". I used a tape measure to mark off the beds.
The garlic was screaming to be pulled; some of the bulbs had already begun to split. The Polish White (no photo) usually grows medium bulbs; I have small and extra small bulbs. Just a few with normal size. Since the size of the bulbs was consistently inconsistent in both beds, I bet you anything it was the compost. I found out much too late that the 'organic' fertilizer store I used was not the correct place. There are two in town. One with high quality compost (I used it the year before. Last years harvest was exceptional), and the other with inferior compost (I used this year by accident). Live and learn.
Oh, and when I was prepping the beds, I forgot to use the blood meal. May have been better that I forgot. I have others tell me they've gone out and found their beds torn from animals smelling the blood. We have all sorts of wild life out here.
A. This was a question submitted from Texas. Okay. Here's the deal on size of garlic. Planting larger cloves results in larger bulbs. Use the smaller ones for cooking or drying.
Spacing. They should be no closer than 4 inches apart if you are pushing size. I use drip tape and I plant on either side of the drip tape in triangular spacing to give them more room.
Bulb size is diminished with salinity. If your chicken manure was pretty hot or the compost was somewhat saline expect smaller bulb sizes.
C:N ratio. If the carbon to nitrogen ratio (amount of nitrogen in the compost) is too high it will diminish bulb size. Ideal C:N ratio is around 20:1. If it gets above 40:1 you have to supplement with additional nitrogen.
Harvested too early. I couldn't tell from the pic but what told you to harvest the garlic? What are the indicators you use to harvest? The bulbs look a bit young but what I could see of the tops there appeared to be some dieback. In northern California they let the tops fall over. We can't do that in Nevada but harvest when about 1/3 of the foliage is brown which is early for other places.
Not enough phosphorus in the bed. Did you apply phosphorus at the time of planting? I supplement with nitrogen through the growing season by sidedressing with my favorite N fertilizer. If organic you can use blood meal or guano or fish emulsion. If not organic then sidedress with ammonium sulfate.
You should know the quality of your compost. They should provide a copy of the test results. Usual problems with compost are salts too high, C:N ratio wrong or too high, high concentrations of toxic minerals such as boron, compost unfinished and needs time to finish. It should not be hot in temperature when delivered. Compost is finished when it has cooled down and the microorganisms have begun to die off.
A little bit of redwood shouldn't hurt. However, it does have a stunting affect. We see this in redwood beds when flowers are grown close to the boards.
Remember to supplement the planting hole with phosphorus...bone meal...not blood meal. Then sidedress with nitrogen every 30 days. Others will say not to sidedress. Try both. Apply nitrogen (blood meal or equivalent) every 30 days along the row a few inches from the bulb on half the plantings. Liquid would be better such as compost tea if you are organic. If animals are a problem maybe use compost tea applications.