Hero Image

Raspberries

Growing Red and Yellow Raspberries in Owens Valley

by Alison Collin, Inyo-Mono Master Gardener Volunteer

 

Ripe yellow and red raspberries. Photo by Kathy Garvey.
Requirements:  Partial sun, shaded from strongest afternoon rays.  Slightly acid soil with pH around 6 -6.5. Good organic matter content in soil with surface mulch.  Cool roots with moist, but not wet, soil. Regular irrigation; surface roots should not dry out.  Support such as parallel wires attached to sturdy stakes; most varieties reach 4-5’.

Growth habit:  Summer bearing have one crop in June and are then finished for the year.  Everbearing have one crop in early summer and a fall crop later.  It is important to know when the fall crop is expected.  If it is too early it hits the worst of the summer heat and berries tend to shrivel, but if it is too late the berries don’t ripen before the frost.

Varieties:  Bababerry is most heat tolerant has a good raspberry flavor and firm berries. Indian Summer has a small summer crop with a heavier fall crop.  Caroline has large berries and a heavy fall crop and has done well for us in Bishop.  Anne is a yellow variety which did well in Bishop, but canes weakened after a few years.  I have tried thornless Joan J. this year for the first time, but the heavy fall crop began in early August and they shriveled in the heat before I had a chance to pick them. Since the weather cooled they have been producing normally. Oregon 1030 is said to be heat tolerant but I have not tried it.  Heritage is readily available and crops well, but the berries tend to crumble.

How to prune:  Raspberries have a biennial growth habit.  In spring new growth appears and grows into canes of varying height depending on the variety.  These are called primocanes. The leaves drop off in winter and the canes mature. The following spring these canes leaf out and small lateral branches bearing flowers appear from the leaf nodes.  The canes are then described as floricanes and will produce ripe fruit in the early summer.  Bees are attracted to the flowers.

Pruning Floricanes or early summer bearers:  Once the crop has finished these canes are removed by cutting them to 4” above ground, leaving only the best new growth from the current season which will crop the following year. (Look for the darker stem bases and old tired looking leaves to show you which ones to cut out). Keep between 6-10 new canes per plant.  In the dormant season cut these canes to about 5½ feet and tie onto wires.

In recent years raspberries that fruit well on the first year’s growth have been developed and these are known as primocane bearers or everbearing.  The crop on the primocanes is produced at the top of the cane and ripens anywhere from early August to November or the first frosts.   In the Owen’s Valley it pays to check the timing carefully!  This year all my berries that ripened in August shriveled in the intense heat at that time, and in the past I had a variety which grew vigorously all summer and produced a huge crop of flowers in October which had not ripened by the first frost!

Pruning Primocane and everbearing raspberries: If growing only for a fall crop cut down all stems in early spring before growth begins. Thin to about 4-5 strong canes and tie in as they grow.  Many varieties have quite heavy crops on the tips, and if not tied in they tend to bow over and touch the ground making them more vulnerable to dirt and insects.

These canes will also provide an early summer crop the next year on the lower parts of the canes that did not fruit in the fall.  To utilize this crop do not cut the stems down in spring, but remove just the top one third of the cane that has already fruited.  After the early harvest these canes can be cut out completely.

Planting:  Plant during the dormant season, late fall to early spring.

Choose either the single row system where individual stems are tied in, or a hedgerow system where a double row of wires form a “box” on the outside of the row.  Plant 1’-2’ apart.

Choose ground that retains moisture but is not waterlogged, completely remove any weeds, and incorporate generous amounts of well-rotted compost or manure.

Dig hole that is wide enough to accommodate roots and deep enough so that the junction of the roots and stem is about 1-2 inches below the surface. Spread the root out and cover them with soil, firm, and water well.  Mulch well with organic matter. Cut stem to about 6”.

Fall bearers may produce a light crop in their first year, and all should produce a crop in their second year.

Irrigation: Raspberries need 1”-2” of water per week during the growing season but less at other times of the year.  Avoid overhead irrigation which may encourage diseases.  Either a double row of dripper lines with emitters every 6” to 1’ or else mini sprinklers are best.  Even moisture is needed to keep the surface roots cool and moist, without being waterlogged which would cause root rot.

Fertilization:  Raspberries do well with organic composts which help to retain moisture. These are used in late fall to early spring. An inorganic 20-20-20 fertilizer can be used in early spring at the rate of 1-1.5 pounds per 25’ row.

Propagation:  Use only vigorous, healthy stock since raspberries can be subjected to viruses and can decline over time.  They can be divided in the dormant season by digging the plant and carefully separating the stems so that each has a good portion of root.  Handle gently since new shoots arise from the fibrous roots and from the base of the old stem and are easily damaged.

Pests and Diseases: Although there are alarming lists of pests and diseases that can affect raspberries, so far mine have generally trouble free, and apart from the odd stink bug I have never had to resort to sprays of any sort. The following link is an excellent resource for any troubles that you might encounter. http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/blackberries.html

Harvesting:   When ripe the berries easily separate from the clusters, leaving behind the central core or plug, so be careful when removing berries from the very thin stems of the lateral shoots since pulling on an unripe berry often breaks or bends these stems spoiling all remaining fruit on that branchlet. (One variety, Jaclyn, has fruits that are very firmly attached requiring a two handed removal technique, and who needs that)? At their peak the berries need to be picked daily or at least on alternate days.

Raspberries have a short shelf life, but they freeze extremely well and can easily be made into jam or a sauce.

Useful links on growing raspberries: