So I had this idea. I live in the very temperate San Francisco Bay Area, in Oakland. I’m in the “banana belt” so it’s warmer than the rest of the city, but it’s still pretty mild. Plums do very well here along with apricots and figs. I’m also growing pluots and some other stuff like a nectaplum, and a Babcock and Saturn peach. But as much as I adore my Santa Rosa plum, what I dream of, what I lust for, is really good yellow peaches and nectarines. But we just don’t get enough heat, I am told. We probably have enough chill for some of the lower chill varieties, but not enough heat.
But how much heat do you need? And for how long? I know that the last week or two before ripening is key, and if you have hot days, you’re more likely to get delicious, sweet fruit.
But what if you could provide that heat in a different way? As a homeowner, I’m always looking for ways to cut costs and I’ve done a lot of research into solar furnaces. The concept is very easy, a box with black pipes/cans/tubes covered with glass/plexiglass/whatever. The tubes heat in the sun and push the air into a duct and you guide it to where you want to go, in a window and it heats the house.
So here’s my idea (sorry for the long set up), what if you put a 2’ high collar around the base of your peach/nectarine tree and blew hot air from a solar furnace in to that area? I do high density plantings of short trees, so I would think the collar would be as high as the first cut. The collar would be black, probably the same size as the berm around the tree. Since the air from the solar furnace is about 130 degrees Fahrenheit, I would think this could possibly create a 10-15 degree difference around the base of the tree and then go up into the leaves.
There are many unknowns here and my own ignorance about which part of the tree needs the heat is one of them. Is it the actual fruit that needs the heat or would heating the actual tree help? I can also see this being a major disaster, but I wanted to float this idea to see if any people smarter than I am could provide some feedback. I would love to grow really good peaches and nectarines…
My simple 2 cents. If it isnt overly costly to do what you are outlining then as Nike would say “Just do it!” If you dont try it you will never know and always wonder if it would have worked. I love to experiment with projects some work some dont, but you always learn something.
I am going to add to my original post. As a seperate idea how about a temporary plastic sheeting installation for those last few days? We all know that the plastic amplifies the temperature on sunny days.
Why not just put a poly covered tunnel over the trees. The temperature is fairly easy to regulate by the amount of ventillation. Keep the ends open and you get 10-20F which should be about right in your area.
Sure, that’s a possibility, but I’ve never heard of anyone trying this. My density is such that it’s probably not feasible to do that, but that’s another idea I will consider. Plus, I’m not that thrilled about the idea of surrounding a tree with plastic.
Well your solar furnace is just the same as a high tunnel. Both gather heat from the sun. A high tunnel sounds easier and will have more certain results. You don’t quite surround the tree with poly. The poly goes on a frame that’s say 1.5 times the height of the trees.
Question have you tried growing nectarines and found them to be no good in your area? If so I think a high tunnel would be the way to go. It would also provide the benefit of keeping rain of of the ripening fruit. I would worry the trees would have an adverse reaction to having hot air blow on them all day. This is just my two cents and I must say I’m not at all familiar with solar furnaces.
Do you have a south wall? The classic British approach is prune to a fan and put a foot from a south-facing wall. I have a few blackberries right by my house and they didn’t even lose all their leaves this last (cold) winter. They are also growing like gangbusters this spring in spite of it being very cool.
My neighbor grows peaches and they fruit intermittently. The fruit is decent, when it does fruit, but not great. They are not watered at all and her “care” of the tree makes me cringe. I planted a Double Delight nectarine this year, so we’ll see how it produces. My plot has a southern facing exposure and I get a solid 11-12 hours of sun a day.
I find this claim dubious. If this were true, you would be able to grow peaches right on the coast, as long as you didn’t over/under water them. Heat does play a part, since you will have greater sugars with more heat.
I assure you that is so.
fig trees are not watered and thanks to this the fruit is sweeter, it is true that in hot places fruit is sweeter, that’s because the increase in temperature decreases the amount of water in the fruit.
a cantaloupe or watermelon are another example, if you irrigates the fruit will be very large with plenty of juice and little flavor, if you do not water the fruit is smaller but contains less water and is sweeter.
do you tomorrow an example, take you and take 1 liter of water in a glass and 50cc of sugar, then take 1/2 liter of water into a glass and 50cc of sugar, drink 2 glasses and tell me which is more which contains more fresh water or containing less
After I pull them out of the dehydrator they are much sweeter, so yeah that is true! Some fruit dried I don’t care for as it is a giant piece of sugar.
We don’t get extremely hot here, but you can produce very sweet fruit. If the weather cooperates and it is dry. To me it’s more a function of water than heat. We get plenty of light.
I hope to document this, this summer, see how high a brix I can get my fruit. If it rains a lot all bets are off! Last year my Indian Free matured October 12th. It was cold by then! Brix broke 20 on a couple of them. In August I expect 28.
accurate, there are fruits that ripen in January as some pears and are sweet, it is also true that many fruit becomes dehydrated(Raisins, grapes, dates, jujubes, etc)
an example, I have a peach tree that today May 26 its fruits weigh about 60 grams (like a plum), at this time the fruits are beginning to gain weight and change color and in just three weeks the fruits are ready to eat and weighing 200 grams with the fruits have gained about 140 grams in just 21 days… this is not a good time to water the tree or many of these extra weight 140 grams of water will be thereby reducing flavor
Show me science. Show me something that backs it up, not anecdotal evidence (pears ripening in the winter isn’t compelling as that is when they ripen, regardless). There’s a reason the sweetest peaches come from the hottest locations. The same with melons and it’s not because they haven’t been watered. I’ve tried growing melons and it didn’t work, plus they have to have a ton of water every day. If you try to under-water a melon, it will die. In California, the best and sweetest melons come from the Central Valley, along with peaches and nectarines. One of the cooler growing regions, the Anderson Valley, is known for its apples…there’s a very good reason they don’t grow peaches, even though the weather is quite dry during the summer. And if you want to use the example of figs not needing water (also not a peach), I will bring up the example of grapes. Having worked in wine, I know for a fact that the heat brings up the sugars. Sometimes too fast, and they abate that by diluting the sugars with more water…but this is a temporary fix since, if the heat continues, the sugars will continue to spike. Yes, they delay it with more water, but only because they need the rest of the fruit to catch up to the sugars.
Also, while the heat brings up the sugar, you need to maintain the juiciness of the fruit…so there is still plenty of water in them. Your example of reducing the water by half doesn’t work since the amount of water stays the same in the fruit. If you reduced the water in a peach by half, you might have more sugar, yes, but you will be left with a shriveled peach (not a dried peach…totally different) and it is not delicious.
Heat has always been what brings sugars up in peaches. Sunlight and water makes the plant grow, but without heat, you are much less likely to have peach worth eating. If this were not true, we’d see many other fruits grown in different, cooler areas. My neighbor’s peach tree (which she doesn’t water and is not near any water source) gets peaches that are just ok and we don’t get a lot of heat here. By your standard, these should be the sweetest peaches ever since they’re not watered. Sadly, they’re not.
So maybe we need a botanist to settle this, but there’s no way you can convince me that simply under-watering a peach tree will make those peaches sweet. You might be able to reduce the water and slightly sweeten the fruit, but that’s not going to give you a jump from 14 brix to 22 brix.
I agree with you that the sweetest peaches, nectarines, pluots, and grapes are grown in warm and even hot climates. But water can also have a large effect on sweetness of those fruits. In my greenhouse I’ve grown Arctic Star nectarines from 14 to 32+ brix. The temperatures are the same every season. The difference as far as I could tell was the water status of the tree. I can routinely get 30+ brix of many nectarines by withholding water.
As to your melons that needed water every day or it would die, well I can’t agree there. That simply isn’t the case in any good melon growing area that I’m aware of. Watermelons are grown dryland in TX and we can get very dry. Mine need water about once a week in mid summer with no rain. Watering every day would be a way to kill them in heavy soils and reduce the sugars in sandy well drained soil.
It’s also difficult to separate the effects of heat and water. In a hot dry climate like the central valleys of CA the summer months will strongly favor trees with a water deficit. It’s so hot and dry it would take a lot of water to result in over watered fruit. It’s the water status of the tree not irrigation amount or timing that affect the fruit.
Show me the science for that. Michigan produces more peaches than 43 other states. We are not warm and the peaches are great. Peaches are not tropical fruits.I bet if I had a greenhouse I could also produce extremely high brix peaches. Some years, well most years it is dry, so the brix in general is decent.
Peach trees will stop growing if temps go over 100. Not really heat lovers. At least according to South Carolina Peach Council executive director Amy Howard London.
I think heat is not going to do anything. But you know you’re entitled to your opinion. I didn’t see any facts about it, or studies noted either. In CA most peaches are produced in the north, where it is cooler.