How To Grow Organic Raspberries?
RAISING RASPBERRY FACTS
- Growing organic raspberries have a dual usage; berries for eating and leaves for tea.
- Raspberry leaves can be dried and used for herbal and medicinal teas.
- Growing organic raspberries contain significant amounts of antioxidants which have been shown to improve your overall vascular health.
- There are two main types to be aware of when growing raspberries: the June-bearing and the Ever-bearing varieties.
- June-bearing raspberries are picked in the late spring typically for around 4 to 6 weeks and produce heavily during this time.
- Ever-bearing raspberries don’t produce as many berries; some varieties will bear fruit throughout the spring and summer, while other varieties will produce once in the spring and once in the fall.
WHEN TO PLANT RASPBERRIES
- Raspberry canes grow for 2 seasons. The first year a new green cane, the primocane, grows; it develops bark, then goes dormant for the winter.
- The cane is called a floricane in its second year; it produces fruit, then dies. The roots, however, continue to send up new primocanes annually.
- Raspberry slips are usually planted in the early spring after the ground thaws in the North.
- In the South, you can plant raspberry slips in the fall or early spring.
BEST LOCATIONS TO PLANT RASPBERRIES
- Raspberries like full sun. We tried planting them in partial shade a few years ago, and they simply never grew well.
- Areas with cold winters are preferable for June-bearing raspberries. New varieties are being developed, though, that grow well in Southern climates.
- Choose soil that drains well, has high organic content, and is slightly elevated if possible. To test drainage, dig a 12 inch deep by 12 inch square hole and fill it with water. If the water drains from the hole in under 3 hours, your soil drainage is adequate.
- Don’t plant too close to trees, and don’t plant your berries where raspberries have been planted recently.
SOIL PREP FOR RASPBERRIES
- Raspberries prefer slightly acidic soil below 7.0 pH level. Optimally, it should be around 6.0, and never below 5.5.
- Compost and composted manure will supply most, if not all, the nutrients needed by raspberries.
- Once you’ve selected the area you’re going to plant your berry slips in, prepare the ground by deep-mixing several inches of compost or composted manure into the soil – at least 12 inches deep into a 24 inch wide row.
- Space your rows 48 to 72 inches apart from edge to edge. This will make the plants 6 to 8 feet apart.
- Remember, you want your berries to have good nutrients for years to come, so you can hardly overdo the compost.
- You can also side-dress existing canes with composted manure to bolster production.
CHOOSING THE BEST VARIETIES FOR YOUR AREA
- Raspberries are in the “rubus” family, and are known as brambles.
- There are three berry color varieties you can grow – red, black, or a combination of red and black known as purple raspberries.
- As always, it’s wise to call your county extension if you’re unfamiliar with raspberry diseases in your area. They’ll be able to advise you on varieties that are resistant to diseases in your local area.
- If you have limited space or live in a rental house where the landlord won’t allow you to garden, you can grow raspberries in containers.
- You’ll want to use a good sterile potting mix to avoid soil pathogens if you’re going to grow raspberries in containers.
- Add plenty of composted manure to the mix, and put it into a 3 to 7 gallon container with several drain holes in the bottom. A five gallon bucket is about the right size for one plant.
- Plant the root slip 3/4 of an inch under the soil surface. Add composted manure annually as needed.
PLANTING RASPBERRIES IN YOUR GARDEN
- In the early spring, after you’ve purchased a variety (or two) you like that is resistant to common diseases in your area from a reputable nursery, you’re ready to plant!
- Soak your plant roots in a compost tea (a cup or two of compost in a 5 gallon bucket of water should work) for around 6 hours prior to planting.
- In your pre-marked rows (prepped per the instructions above), insert your shovel as deep as it will go into the soil, and with a rocking-back-and-forth motion, open up the soil and insert the raspberry plant to where the dirt covers the roots. You should be able to tell where the root ends and the cane starts.
- Make sure you spread the roots laterally to give the plant roots a good start. Put one plant every 24 to 36 inches apart in your rows. The distance between the rows should be around 6 to 8 feet.
- It is a good practice to “trellis” your raspberries to keep them from falling over as the canes can grow up to 8 feet tall.
- The way we do it is to use 4 x 4 inch posts with 36 inch 2 x 4’s nailed horizontally at 2 feet from the ground and 4 feet from the ground (you can also add a third horizontal bar at 6 feet off the ground if you need to). Then string wire between the horizontal 2 x 4’s to keep the canes standing vertically.
- During the mid to late summer, as the primocanes are growing rapidly, you’ll need to make sure, every couple of days, that the canes stay inside the wires as it becomes difficult to try to shove them back under them if they get too tall.
GETTING THE MOST FROM YOUR RASPBERRIES
- The more bees you have in your patch, the more berries you’ll harvest.
- Keep the area between the rows weed free by rototilling regularly or mulching. Another option is to plant a cover crop.
- As mentioned previously, a trellis system or other supports is key to keeping your plants vertical – and production high.
- It’s a good practice, in the spring before the leaves begin growing, to prune the tops of your floricanes to 5 or 6 feet in height.
- One trick for getting more fruit is to cut off the primocanes at about 30 to 36 inches. This will force them to put out branches, giving you more fruit production that is easy to reach as well.
- After your fruit has been harvested, cut off all the dying floricanes at ground level to give the primocanes as much room as possible to grow.
- In the spring, thin out the new floricanes so that just the thickest and strongest canes remain. These will produce more fruit than leaving all the canes in the ground.
- If you need to, you can side-dress your canes with composted manure in the spring. Usually, if you’ve mixed in plenty of composted manure prior to the initial planting, you shouldn’t need to add much.
- This past gardening season we tested a liquid organic leaf spray fertilizer called Organic Garden Miracle™. We sprayed most of our garden plants with OGM™. The sprayed veggies were more robust than the unsprayed plants, and the flavor was superior as well – sweeter and juicier. We’re excited this year to continue the experiment as we were impressed with the size and flavor of the garden crops we sprayed last year.
MULCHING & WEEDING
- Lawn clippings and barley straw are two of the best mulches for raspberries.
- I like to spread a few inches of mulch between the rows and around the plants to keep the soil moist and the weeds under control. It also provides organic matter for your soil over the summer as it begins to decompose.
- Too much straw may become a haven for mice or other rodents, so don’t get too deep with your mulch.
- If you choose not to mulch, rototill or hand-pull the weeds between the rows and hand-pull the weeds around the plants.
HYDRATING (WATERING) RASPBERRIES
- As mentioned above, mulching will reduce your need to water your raspberries, but you’ll still need to water between 1 and 2 inches per week all summer.
- It’s always a best practice to avoid overhead watering, but if you have no other option, water early in the day to avoid too much dampness in your plants which can lead to fungal diseases.
- If your soil is sandy, you may need to water less volume but more frequently. Don’t over-water as raspberry roots require a good amount of oxygen.
COMPANION PLANTING AND ROTATION CONSIDERATIONS
- Turnips and yarrow are considered good companions to raspberries as they repel the Harlequin Beetle.
- Garlic accumulates sulfur which is a natural fungicide. Coupled with raspberries, garlic will prevent fungal diseases. It is also effective in keeping many insect pests at bay as well.
- Tansy is a poisonous flower that repels various pests including ants, Japanese beetles, cucumber beetles, and squash bugs. Don’t let it spread to your pasture, though, as it’s not good for some livestock.
- Wormwood, a bitter herb, repels insects and some animals. Don’t eat it; you may get a pretty good stomach-ache too!
- As they’re in the same family, keep raspberries out of areas where blackberries, boysenberries, or loganberries are growing.
- Don’t plant around potatoes either as they’ll make your raspberries more prone to blight.
- Never re-plant a new raspberry patch where the old one has been. However, if your soil is uninfected by fungal diseases, nematodes, or other pathogens, you should be able to leave your raspberry patch in the same location up to 15 years.
- Avoid verticillium wilt by avoiding planting raspberries anywhere eggplant, tomatoes, potatoes, or strawberries have been planted in the past 5 years.
- When raspberries are a bright red and can be easily removed from the canes, they’re ready to pick.
- If you’ve had a recent rain, make sure to pick the ripe berries immediately or they’ll mold within half a day if it’s warm.
- If it is breezy, it’ll dry things out before mold sets in.
- Harvest your berries early in the day when it’s cool; they’ll last longer.
- Harvest at least every other day during the height of the season. This will prevent your fruit from getting over-ripe and molding.
- When you pick raspberries, don’t layer them more than a few deep or they’ll turn the bottom layers to mush. Pick with care to avoid crushing these tender berries.
- Once you’ve picked your raspberries, refrigerate them as soon as you can. They’ll keep up to a week in a cool refrigerator.
- Raspberries are great eaten fresh on ice cream, on flake cereals with half-and-half, or on shortcake with whipped cream, to name a few delightful ways to gain weight.
- Raspberries make excellent jam (with and without seeds), and are good frozen whole or pureed. If you puree raspberries and strain out the seeds, put them in ice trays and freeze them for smoothies. Mmmm!
- If you don’t mind seedy smoothies, just freeze the berries whole on jelly roll pans, then remove to zip lock-style bags or plastic cartons for later usage.
- You can also spread pureed and strained raspberries in pans, place in the oven at very low temp, and make raspberry fruit leather. We did this when I was a kid, but I haven’t done it recently.
PREVENTATIVE AND NATURAL SOLUTIONS TO COMMON PESTS
- Sap Beetles love to eat over-ripe raspberries. They’re also known as “picnic” beetles.
- Sap beetles are about ¼ inch long and black with 4 yellow-orange spots on their backs.
- The easiest way to prevent an infestation of this beetle is to not allow your berries to get over-ripe.
- You can pick these beetles to reduce their numbers, dropping them into a bucket of soapy water to drown them.
- Aphids are tiny little pests that come in a variety of colors from green to brown to red to black.
- Aphids typically congregate on the undersides of your raspberry plant leaves, sucking the sap from the leaves and leaving a sticky residue called “honeydew” behind.
- If you see leaves crinkling up you’ll likely find aphids on the leaves.
- Aphids can be controlled by removing the infected leaves and destroying them along with the attached aphids.
- You can also spray them with an organic insecticidal soap spray, or even knock them off with a pressure-spray nozzle, although it’s better not to get your plants wet during harvest-time.
- Cane borers chew into your canes to lay eggs and feed on the inside of the canes. The larvae also feed on the inside of the canes as well.
- If you discover these pests, cut down any affected canes an inch below where wilting is occurring and destroy them.
- If the infestation is heavy, organic rotenone powder may be used, but use this as a last ditch effort as it will also kill pollinating insects which is highly undesirable.
- Leaf rollers are the larvae of a small moth that are about 3/4 of an inch long, pale green or light brown, and have dark heads.
- Leaf rollers will eat raspberries, and when ready to form a cocoon will weave a silky web on a leaf and roll it inwards. Hence the name “leaf roller.”
- Parasitic wasps and flies can be imported to rid your patch of these pests. You can also use organic Bacillus thuringiensis (Bt) if the infestation is severe. It’s best not to use even organic pesticides, though, unless absolutely necessary, as they take out both good and bad bugs.
- Spider mites are tiny pests, that, if you look at under a microscope, have eight legs.
- Spider mites cluster on the undersides of raspberry leaves, sucking sap and creating yellow spots on the leaves.
- Spider mites seem to be the worst in drought conditions when the plants are weaker.
- Spraying these mites with water can get rid of them if they’re not too plentiful. Insecticidal soap spray can also take care of them.
- Avoid using too much nitrogen on your raspberries as it seems to encourage both mites and aphids.
RASPBERRY DISEASES AND CURES
- Winter injury may occur in your raspberry plants if winter temperatures drop below -20°F. Purple and black raspberries may be damaged at -5°F.
- Mulching raspberries will prevent most damage from occurring.
- Anthracnose is a reddish-purple lesion that shows up on primocanes. The centers of the lesions turn gray to brown over time and the margins become raised and purplish.
- These lesions will girdle the canes and cause them to dry and crack, often killing them. If they survive winter, the floricanes will produce irregular fruit and branches.
- The best prevention, if anthracnose is common in your region, is to purchase resistant varieties.
- It also helps to control weeds, and water early in the day or use drip irrigation as anthracnose is spread by splashing water.
- Applying lime sulfur during the early spring can also reduce anthracnose.
- Cane blight appears as lesions that may be gray, black, or brown and appear like pimples.
- Infected canes often become brittle and break near the lesion. The canes may wilt, and auxiliary branches may die.
- The best prevention is purchasing blight resistant stock before planting if it’s a problem in your area.
- Avoid overhead watering for the same reasons as in the anthracnose section above and control the weeds.
- Destroy any infected canes, and apply lime sulfur in the early spring if your plants had any infection the previous year.
- Spur blight is another blight that causes lesions on the nodes of primocanes. The infections starts on the leaves and moves to the stem.
- The infected leaves turn yellow and brown and die. The cane lesions appear purplish to brown. The following spring any buds near the infection will not bloom.
- The best cure is prevention by planting resistant varieties. Avoid overhead irrigation and too much nitrogen. Control the weeds. Thin the canes. Plant in well-drained soil.
- Apply lime sulfur in the early spring if your plants had any infection the previous year.
- Gray mold causes raspberries to rot and blossoms to rot as well. It is spurred on by cool, wet weather.
- Purchasing resistant varieties is the best preventative against gray mold.
- Using drip irrigation can help prevent the mold. Don’t over-fertilize. Control weeds. Remove infected canes. Don’t overwater. Harvest ripe berries promptly.
- Phytophthora Root Rot is caused by a soil-borne fungus. Symptoms include yellowing and wilting leaves, water-soaked lesions near the base of the canes, and reddish-brown root tissue.
- Over-saturated soil is often a cause of Phytophthora Root Rot and can be prevented by planting your canes in well-drained soil, not over-watering, purchasing resistant varieties, and controlling weeds.
- Verticillium Wilt is another soil-borne fungus that can cause the entire raspberry cane to wilt and die.
- The sapwood of infected canes will often be stained reddish-brown.
- To avoid verticillium wilt, purchase resistant varieties, plant them in well-drained soil or raised beds, don’t over-water, use drip irrigation if possible, thin the canes, and destroy infected plants if you have an outbreak.
- Raspberry Leaf Spot shows up on the top surface of raspberry leaves as tan, white, or grayish spots. Sometimes the center of the spot will drop out, making it appear as though the leaf has been shot.
- The prevention of this disease is the same as the diseases already discusssed – purchase resistant varieties, plant them in well-drained soil or raised beds, don’t over-water, use drip irrigation if possible, thin the canes, and destroy infected plants if you have an outbreak.
- Powdery Mildew appears on the underside of leaves as a gray to white powdery growth. While it is common to raspberries, it’s not generally a major problem to the health of your plants.
- The prevention of this disease is the same as the diseases already discusssed – purchase resistant varieties, plant them in well-drained soil or raised beds, don’t over-water, use drip irrigation if possible, and thin the canes to allow good air circulation.
- Rust Fungi appears on both sides of raspberry leaves as yellowish-orange spots. They typically don’t affect the health of the plants or fruit of red raspberries, but can be a serious threat to black raspberries.
- Again, purchase resistant varieties, plant them in well-drained soil or raised beds, don’t over-water, use drip irrigation if possible, thin the canes to allow good air circulation, and remove and destroy any infected black raspberry canes.