Days to germination: Not usually grown from seed
Days to harvest: 6 months, depending on variety
Light requirements: Full sun
Water requirements: Water regularly and consistently
Soil: Rich with added compost or manure
Container: For smaller bushes
Raspberries are a wonderful fruit that even gardeners in very northern regions can enjoy. The plants are hardy to zone 2, so they don’t mind cold winters.
Raspberries can be eaten raw or cooked. Usually used in dessert dishes, though not exclusively. Many savory dishes get a hint of sweetness from a few raspberries too. They are high in manganese, vitamin C and folic acid. Surprisingly, you will get about a third of your daily requirement of fiber from a cup of raspberries.
Wild raspberries have a tendency to spring up in the most inhospitable places, but ones cultivated for their fruit should be planted in more fertile ground. Though they are perennials, raspberry plants will usually only produce a crop of fruit for 8 to 10 years before dying out.
Starting from Seed
You can start raspberries from seed, but most home gardeners purchase seedlings. Raspberry seedlings from a nursery will look like bare sticks with roots, usually no leaves. That’s what you are looking for. See the “Growing Instructions” section on the different kinds of raspberries.
Your seedlings should be planted around 2 feet apart, and at least 4 feet between the rows so you have good access to the plants. Prickly raspberries are not fun to reach through. The new plants should be planted an inch or two deeper than the level they were originally growing.
Get your seedlings in the ground either in the late fall, or first thing in the spring. Add some compost into the soil as you are digging up for planting.
The most difficult part about growing raspberries is the pruning. The way the plant grows, each branch or “cane” only produces fruit once. After that, you need to prune it back to make room for new canes. You can forgo this step if you really want to, but your plants will grow very large and produce a lot less fruit without at least a minimum of cutting back. Not to mention the difficulty of trying to pick berries through all the brambles.
How you prune will depend on the kind of berries you are growing. The easiest ones are called “everbearing” raspberries. This variety of berry will produce fruit on canes just sprouted that spring.
The other kind are “regular” raspberries, also called summer raspberries. They sprout canes that won’t produce fruit until their second year, and they are a bit more complicated to prune properly because you have to keep track of which branches had fruit and which didn’t.
With everbearing raspberries, you can cut back your entire plant in the fall after picking the last of the berries. Prune all the canes down to about 5 inches high. The next spring, all the new canes will produce fruit for a fall harvest. If you are new to raspberries, this is the route to take.
For regular raspberries with 2-year growing canes, you have to prune each cane back after you’ve picked the fruit off of it. That way, you’re removing any canes that have produced fruit and left the 1-year canes that haven’t.
You should also cut out any skinny or dead canes, to keep the bush under control.
If you are growing everbearing raspberries, you probably won’t need to provide any support for your plants because you will only ever have 1 year’s growth to deal with. For summer berries with 2-year canes, your bushes can start to get big. The canes can get bent over or droop down to the ground.
The usual way to support raspberry canes is with horizontal support, rather than a vertical pole or trellis. Put a sturdy stake at each end of your row, and run a taut cord or wire between them. Tie your canes to the wire. Alternatively, you can have 2 strands of wire (one in front, and one behind the plants) to hold the canes up without tying. The lines should be about 3 feet high, so you will have to wait until your canes are around 4 feet long before the support will be necessary.
Every spring, give your plants a feeding with compost or a standard fertilizer blend. Water regularly, paying special attention when the fruit is starting to set. You should not let the plants dry out while the berries are growing.
You can grow raspberries in large pots (at least 16 inches across and a foot deep), but you should take extra care with their pruning so they don’t outgrow the container. Keep your potted raspberry bush down to about 4 or 5 canes at the most. Because they will be growing in the same pot for many years, you should fertilize generously. A feeding in the early spring and late fall is ideal.
Pests and Diseases
The raspberry cane borer will lay her eggs in the very tips of your canes, and the larvae will then eat their way down towards the main plant. If the tips of your canes are dying, check for small holes. If you see a pair of holes or grooves, you have a borer. Cut the cane about 2 inches farther down and dispose of it.
Another raspberry-specific problem is the raspberry leaf spot fungus. New leaves will start to get dark green spots on them, that eventually turn gray. The rotted patches will then fall right out of the leaf, leaving a hole. If the fungus is too widespread, your plants could lose all their leaves and die. Treat with a fungicide as soon as you see it developing. To prevent leaf spot, prune out extra or dead canes to help the air circulate better around the plants.
Once the berries come in, you will want to watch out for birds and rodent pests as well. Harvest as soon as they are ripe.
Harvest and Storage
You’ll know your raspberries are ripe when they pull away from the plant without much effort. If they are securely attached, then they are not ready to pick. Overripe berries will be soft and will probably come apart when you pick them. When you pull the berry off, it will leave behind a small core from its middle, leaving a hollow berry.
Wear long sleeves when picking raspberries. The canes are very prickly though the berries themselves are not.
Raspberries are quite delicate. If you are harvesting a lot of plants, don’t just use one big bucket or you will crush the ones at the bottom. Empty your berry bucket frequently and gently. Fresh berries should be used within 4 or 5 days, stored in the fridge.
You can freeze raspberries for storage up to a year. It’s a good idea to spread them out on a cookie sheet while they freeze, and then put them in a container. This prevents them from freezing together. Thawed berries are fine for cooking, but they will lose their texture.