How far South Can You Grow Raspberries?
Q. Jon, via the YBYG Facebook page, writes “I’m trying to keep my blackberry and raspberry vines healthy in a winter that goes from 30’s one day to near 80.” I asked Jon exactly where that might be and he responded “I’m in the ARKLATEX,” (the area where Arkansas, Louisiana and Texas crash together). Then he adds “If I read the maps correctly, it’s USDA Zone 8b—oh, and my plant is in a pot.”
A. Well, this could be a very short answer: You can’t grow cane fruits like raspberries in pots because the roots need to spread out far and wide for their life cycle to continue. You can grow blueberries in a pot, because they are shrubs that do not spread, but with raspberries, the more room you give them, the more berries you’ll get no matter your clime.
To answer the main part of the question, you can grow raspberries in a warm climate if you grow them in a specific area and cheat a bit (remember kids: Cheaters Always Win!)
Raspberries require a certain number of {quote} 'chilling hours' to bear fruit (nights in the mid to low 40s or colder). 'The book' says that the most basic types can only be grown as far South as USDA Zone 6. But I know of patches that thrive in zones 7 and 8. The trick is to plant a designated 'low chill' variety in a spot that gets morning sun and afternoon shade.
Yes, I say "morning sun and afternoon shade" for just about every plant, but the further South you are, the more universal that advice becomes. (Except for dogwoods, where the need for afternoon shade always applies.)
Anyway: In the Northeast, mid-Atlantic, Midwest and other cold winter regions, raspberries should get full sun. So should crops like tomatoes and peppers. But when you get to areas where winter is mostly mild and summers are intensely hot, those same plants need a break late in the day.
As I have often explained, {quote} "full sun" means full sun in the North, a little shade in USDA Zone 7, and serious afternoon shade in the higher Zones. It's easy to forget that catalog and online descriptions have to try and cover the entire country when, in reality, plants are going to have very different needs in Minnesota than San Diego (where raspberries are difficult to impossible to grow.)
Planting time? In the Spring. You buy dormant canes mail-order or from a local nursery and plant them in the ground about the same time as your tomatoes. If you know someone who's already growing raspberries nearby, see if you can bum a few plants from them in the spring, when lots of new shoots pop up in established patches; those canes should already be adapted to the local climate. At the very least, see if they know the variety name and seek to purchase the same plants.
“Bare root” canes will arrive brown and dry. Get them ready for planting by soaking them in a bucket of clean water (NOT tap water; it’s bad for you and your plants) for at least eight hours and as much as 24. Use a brick to hold them under the water so they get good and saturated. Fresh green canes just need to be watered in well.
There are two basic 'types' of red raspberries. The most common are known as 'fall-bearing', which is half-right; and 'ever-bearing' which is technically correct (kind of). I grow {quote} ‘fall-bearing’ varieties, which actually fruit twice a year. Their growing sequence is highly unusual: New canes sprout up from the soil in the Spring, grow all season long and then produce a nice crop of berries at the very tips of the canes in the Fall; often late Fall.
Then those canes go dormant and may look dead, but don't dare prune them—because the following year they'll sprout new green growth and produce a big flush of berries all up and down those canes just as Summer arrives.
I never share any raspberries in the Fall; there just aren’t enough. But I give away pints when that 'second year' late Spring harvest comes in; it's a ratio of almost 10 to 1. That so-called 'second crop' is enormous. So don’t do anything to your first-year canes except dead head them by pruning off the very tips when the fruit is finished or frosted.
The other basic type of raspberry is 'everbearing'; sometimes called 'summer bearers', they pretty much fruit all season long. Consult your local county extension service when choosing varieties; they know which ones should do best in your area.
Unfortunately, some extension services are not the best when it comes to what we call 'cultural care', as many continue to recommend high potency chemical salts as fertilizers, which is especially K-RAY-ZE with raspberries, which do best in poor soil with little to no added nutrition; maybe a couple shovelfuls of compost every once in a while, plus watering while getting established. If you foolishly use chemical fertilizers on these plants, you'll get insects, disease and inferior fruit.
What raspberries need most is room to spread; they are not well-behaved plants, and the best patches are planted with room to roam. They also need superior drainage, especially in climes that typically get a lot of rain.
They will need extra water during droughts. And that afternoon shade is essential in the warmer zones! It isn’t all that hard. Set up some big hoop house structures and pull shade cloth over them; shade cloth is easy to find and comes in different levels of protection. Or beach umbrellas! Or patio umbrellas!
Or use your imagination; just don’t let the plants go without afternoon shade.
Or move North.
A. Well, this could be a very short answer: You can’t grow cane fruits like raspberries in pots because the roots need to spread out far and wide for their life cycle to continue. You can grow blueberries in a pot, because they are shrubs that do not spread, but with raspberries, the more room you give them, the more berries you’ll get no matter your clime.
To answer the main part of the question, you can grow raspberries in a warm climate if you grow them in a specific area and cheat a bit (remember kids: Cheaters Always Win!)
Raspberries require a certain number of {quote} 'chilling hours' to bear fruit (nights in the mid to low 40s or colder). 'The book' says that the most basic types can only be grown as far South as USDA Zone 6. But I know of patches that thrive in zones 7 and 8. The trick is to plant a designated 'low chill' variety in a spot that gets morning sun and afternoon shade.
Yes, I say "morning sun and afternoon shade" for just about every plant, but the further South you are, the more universal that advice becomes. (Except for dogwoods, where the need for afternoon shade always applies.)
Anyway: In the Northeast, mid-Atlantic, Midwest and other cold winter regions, raspberries should get full sun. So should crops like tomatoes and peppers. But when you get to areas where winter is mostly mild and summers are intensely hot, those same plants need a break late in the day.
As I have often explained, {quote} "full sun" means full sun in the North, a little shade in USDA Zone 7, and serious afternoon shade in the higher Zones. It's easy to forget that catalog and online descriptions have to try and cover the entire country when, in reality, plants are going to have very different needs in Minnesota than San Diego (where raspberries are difficult to impossible to grow.)
Planting time? In the Spring. You buy dormant canes mail-order or from a local nursery and plant them in the ground about the same time as your tomatoes. If you know someone who's already growing raspberries nearby, see if you can bum a few plants from them in the spring, when lots of new shoots pop up in established patches; those canes should already be adapted to the local climate. At the very least, see if they know the variety name and seek to purchase the same plants.
“Bare root” canes will arrive brown and dry. Get them ready for planting by soaking them in a bucket of clean water (NOT tap water; it’s bad for you and your plants) for at least eight hours and as much as 24. Use a brick to hold them under the water so they get good and saturated. Fresh green canes just need to be watered in well.
There are two basic 'types' of red raspberries. The most common are known as 'fall-bearing', which is half-right; and 'ever-bearing' which is technically correct (kind of). I grow {quote} ‘fall-bearing’ varieties, which actually fruit twice a year. Their growing sequence is highly unusual: New canes sprout up from the soil in the Spring, grow all season long and then produce a nice crop of berries at the very tips of the canes in the Fall; often late Fall.
Then those canes go dormant and may look dead, but don't dare prune them—because the following year they'll sprout new green growth and produce a big flush of berries all up and down those canes just as Summer arrives.
I never share any raspberries in the Fall; there just aren’t enough. But I give away pints when that 'second year' late Spring harvest comes in; it's a ratio of almost 10 to 1. That so-called 'second crop' is enormous. So don’t do anything to your first-year canes except dead head them by pruning off the very tips when the fruit is finished or frosted.
The other basic type of raspberry is 'everbearing'; sometimes called 'summer bearers', they pretty much fruit all season long. Consult your local county extension service when choosing varieties; they know which ones should do best in your area.
Unfortunately, some extension services are not the best when it comes to what we call 'cultural care', as many continue to recommend high potency chemical salts as fertilizers, which is especially K-RAY-ZE with raspberries, which do best in poor soil with little to no added nutrition; maybe a couple shovelfuls of compost every once in a while, plus watering while getting established. If you foolishly use chemical fertilizers on these plants, you'll get insects, disease and inferior fruit.
What raspberries need most is room to spread; they are not well-behaved plants, and the best patches are planted with room to roam. They also need superior drainage, especially in climes that typically get a lot of rain.
They will need extra water during droughts. And that afternoon shade is essential in the warmer zones! It isn’t all that hard. Set up some big hoop house structures and pull shade cloth over them; shade cloth is easy to find and comes in different levels of protection. Or beach umbrellas! Or patio umbrellas!
Or use your imagination; just don’t let the plants go without afternoon shade.
Or move North.
