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Organic Gardens/Chill Hours In Long Island


Looking for grow figs, blueberries, and raspberries in Nassau County.  How many chill hours do we experience in LI?

I have good news and I have bad news.  

First, the not-so-bad: Legitimate data for Chill Units -- aka Chill Hours, or "Winter" :) -- can be hard to come by in this region.  You can calculate it yourself, but it would take time, as in months of time.

Which brings us to the pretty good news.

Because Chill Units occur in the midway point of the yardstick (not just the chillier or warmer days), they are a concern mainly for people living to the south or the north.  Long Island has just the right number of Chill Units to set the most fickle fruits into production.

Warmer climates of course have a problem caused by a shortage of Chill Units.  Cooperative extension people analyze these numbers to support the agricultural industry.  Here's what they do for farmers in California, where they have to worry about Estimated bloom dates for pistachios:

From UC Davis come "Chilling Accumulation Models":

And for the pistachio-growers UC Davis posts this:"

Here is what the Ag people do for farmers in Dixie:

Actually, as you head farther south, chilling data is as necessary as a compass, a potential weather crisis that can make you rich or poor.  And in places like Alabama, where they have to worry about it hitting 70 degrees on a winter day and re-setting the cycle back to Day 1, chill units rival tornadoes in their unpredictibility:

Long Island may not be paradise, but one thing we do NOT have to worry about is 70 degree days in the middle of February... yet. Snowfall may vary, but our weather temps are not extreme (due to the water water everywhere situation).

All of which explains why there is little public data surrounding chill. Raspberries and Blackberries grow wild here. Figs are more susceptible to minimum temperature issues -- but there are good varieties Italian expats grow in the backyards all over Glen Cove.

Basically, Long Island farmers who care at all about Chill Units do their own stats -- vineyards for instance, which take pretty much every statistic to a new level anyway.

But Long Island temps being moderate, this is an undertaking only for the obsessed. Life is too short to worry about that HERE.

Q: How many Chill Units do we have in a typical Long Island Winter?

A: Just the right amount.

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There is NO EXCUSE today for a gardener to use chemicals. Perfect Lawns? Pristine Roses? Immaculate Flowers all Summer long? If you live in the Northeast/Atlantic Coast, I'll guide you down the non-toxic road to Organica - and you will not believe how easy it can be. Yes, it can be complicated, but backing off from Ortho and Scotts is not as hard as you think. Your neighbors won't believe their eyes. I have intelligent answers on soil care, bug killing, weed control and fungus-freedom!


I have college credits in horticulture and botany, and 30 years of gardening for personal pleasure. Plus I am a volunteer docent at the local botanical gardens. But a person's real gardening skills are learned from trial and error. I am strict about not using chemicals in the garden. Always have been. Always will be.

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