I like to push the limits of winter chill in my San Diego inland environment, located in the Poway/Rancho Bernardo area. I thought my experiences might help others in Southern California who are deciding which apricot varieties to try. The closer to the coast you get, the worse the experience seems to be, from talking to others.
I write these in order of crop harvest. Some of these are just multigraft branches, and I only have 4 years of experience in this location.
Royal Rosa - Harvest mid May. Rated at 500 chill hours by Dave Wilson nursery, this variety fruits every year, and takes all the abuse I give it. Fruit was at times good but nowhere near as good as Blenheim. Very vigorous tree. Lacked intensity of flavor and acidity. Overall flavor grade B-.
Goldkist - Harvest late May. Rated at 300 hours. Produced every year I had it. Removed it when I changed landscape design. Had some acidity. Overall flavor grade B.
Katy - late May. Rated at 200-300 hours. Flavor poor, grade D. Production poor.
Tomcot - early June. Rated at 500 hours. Only had one large branch of this variety but it seemed to require more chill. I really enjoyed the different flavor. More floral. Sweetness was mild. Flavor grade A-, probably would say B+ if I got enough fruit to get bored of its uniqueness. Most years does not fruit much. I only had one branch though.
Blenheim (Royal) - Harvest early June. Rated at 400 hours. Known for being low chill. Fruits almost every year if I do summer pruning rather than winter. The flavor is amazing. No other tree compares to this. Silicon Valley was once full of orchards of this variety. The southern California Blenheim is sometimes actually better, and I know that comment will be controversial, and it varies by the year, but I think they are sweeter here. This may just be from drought conditions at harvest. Flavor grade A+.
Tropic Gold - Harvest the same as Blenheim. Flavor the same as Blenheim. This variety exists because a tree cropped more reliably than Blenheim in Camarillo, yet tasted like Blenheim. LE Cooke marketed it but I can not find evidence they were ever able to patent it. I remain unconvinced this variety is anything other than Blenheim. Maybe something else caused it to crop better? Flavor grade A+. Prove to me that this variety is anything other than Blenheim. Production was not better than Blenheim either.
Harcot - supposed to be July, fruited in early June for me. Rated at 700 hours, never produced much but gave a few each year and was healthy. Flavor grade C, but was probably intended for a different climate
Moorpark - I have had one fruit from a not completely mature tree. It was very good, more mild than Blenheim. I like the diversity but Blenheim is still my favorite. The tree appears to be dwarfing naturally, and anyone experimenting with this variety should consider a more standard size rootstock. Flavor grade A
Earli-Autumn -Harvest was in July, not exactly Autumn. Rated at 500 hours. It was a late season Royal Rosa, fruited heavily every year and the fruit was decent. I pulled mine out. Flavor grade B.
Autumn Royal - Harvest was in July. Rated at 400 chill hours. Fruited very heavily every year. Got pit burn. I never had a single fruit that tasted as good as Royal, even though this variety is a sport mutation of it. Some were okay. I suspect that these sport mutations are really just defects in ripening, and that does impair flavor. Pit burn, cracking, and insects destroy the crops. I chopped it down. Flavor grade B-, not counting pit burn. D if you include that.
Autumn Glo - Harvest was early August. Rated at 500 chill hours. Very vigorous tree did not produce well, possibly because it was still growing. I ended up removing it when I changed my landscape structure. It gave a few fruit each year, never a full crop. They were never amazing, but decent for the late season. Flavor grade B. Production grade D.
Recommendations:
For Southern California coastal, you are in a totally different climate and this information is probably only marginally helpful to you. Experiment and post your results! Try Tropic Gold and Blenheim and see if TG actually fruits more. I am skeptical.
For Southern California inland, plant Blenheim. Maybe you wont get a full crop every year, but that will just make you happier the years you do. The flavor here is amazing.
Chill estimates:
Royal Rosa, Earli-Autumn, and Autumn Royal appear to be lower chill than expected. Very productive.
Autumn Glo, Harcot, and Moorpark are demonstrably high chill, which is no surprise. Katy may be high chill also, which is a surprise. Tomcotās 500 hours are real.
Please share your own experiences?