Ideal Growing Conditions for Raspberry Plants

The key elements to raspberry success are careful selection of plant type, a good solid trellising system, and husbandry techniques that match the needs of the plant.

everbearing raspberries — called fall bearing by some—begin production in our area in July. The canes are usually so loaded down, they bend far over their support wires. Summer-bearing varieties generally fruit earlier, usually by a few weeks.

We added the yellow-tinged 'Golden', which is everbearing. Other similar varieties are 'Fall Gold', 'Golden Summit', and 'Golden Harvest'.

How many plants, and how big a patch?
Raspberries multiply precociously, prodigiously, and prolifically. If you plant one cane this year, you will have a dozen or more in the same spot next year. Raspberries are joyfully exuberant about procreating by underground runners, poking up impressive numbers of healthy new plants all around your original patch. I don't consider this to be a problem, though, because one whack of the hoe takes care of them. You can also present them to a friend or use them to extend your patch.

Our two-row raspberry patch is 7 feet wide by 33 feet long. If I were to do it all over again, it would be 9 or 10 feet wide to allow more elbowroom for picking between the rows. We have 3 feet between rows, which is just barely enough. Four to 6 feet would be better.

Raspberry plants hate wet feet, and they are gross feeders. We addressed these two critical points by building a 20-inch-high raised bed and filling it with a mixture of four-fifths good garden topsoil blended with about one-fifth sand, peat, and well-rotted manure. If, like us, you have acidic soil, you will also need to add some lime, because raspberries prefer a soil pH of around 6.0.

If you have rich, deep soil that drains well year-round, you can simply plant your raspberries in a permanent garden site. Not us. The Pacific Northwest gets rain all winter, and many gardeners lose raspberries to root rot because they make the mistake of planting their raspberries' fussy little toes directly in the ground, which is often soggy clay covered with a skim of topsoil. We also experience a two-month drought most summers. Raised beds allow us to have deep soil that holds moisture evenly yet drains well.

It is important that you do not establish your raspberry patch in an area where you have recently grown tomatoes, peppers, or potatoes, to avoid verticillium wilt, which these vegetables can carry, and raspberries can catch.

I soak bare-root plants in a half-strength solution of vitamin B1 growth stimulant (1/2 teaspoon per quart water) for about six hours (see Give your rootstock a healthy start). Don't delay planting. The small plants will not stand for soaking longer than a day in the B1 solution, and they will die quickly with dry roots. Should you receive dormant bare-root plants by mail before you are ready to plant, put them in the fridge to keep them dormant.

Bare Root Plants;
Plant in a 1-foot-deep, 1-foot-wide hole with a handful of rotted manure and organic fertilizer.

Water well.

Mulch to retain moisture.

Have on hand some well-rotted manure, mushroom manure, or compost; organic fertilizer (see Organic fertilizer mix for raspberries), or 4-20-20; a water source; and some mulch.

Dig a hole 1 foot deep and wide per plant. In our case, we set the plants 3 feet apart in the row. Put a handful each of rotted manure and fertilizer in the hole. Add some water, pop the plant in, then carefully tuck the soil around and over its spread roots to make a small depression or basin at the surface, a place for rainfall to accumulate. Sprinkle some more rotted manure in this depression to provide a jump start for growth, then cover the ground around the plants with your mulch — no more than 3 inches deep.

Organic fertilizer mix for raspberries
I make this up each year in a big rubber horse-feeding trough. If you use this mix just before your raspberries blossom, reduce the amount of canola/fish meal by half (to 2 parts), as the plants need less nitrogen then.

4 parts canola seed meal or fish meal
1 part dolomitic lime (offsets the acidity of the seed meal)
1 part rock phosphate or 1/2 part bone meal
1 part kelp meal

A T-bar trellis lends needed support

Pruning for a long harvest season

The smooth green 1-year-old canes and the rougher brown 2-year-old canes are easy to tell apart. Each spring, 1-year-old canes are trimmed back to below the fruiting area, and 2-year-old canes are removed completely.

The main purpose of pruning is to get rid of older canes in favor of newer canes that will produce fruit. In late summer, some of your newly planted canes will begin to fruit at the top of the cane and continue into the fall. In the early spring of the following year, while the plants are still dormant, it's time to prune these now 1-year-old canes, and here is where we do something special.

The common method of pruning everbearing raspberries is simply to cut all of the canes down to about 1 inch from the ground. Though it's an easy way to go, this method eliminates the July crop. Fruiting doesn't begin until early fall, the reason some raspberry growers call everbearing raspberries "fall bearing." (This method is useful, however, if a disease has developed in your patch.)

Instead, the first spring, we cut the 1-year-old canes back to below the fruiting area, level with the top support wire. These shortened canes begin fruiting in July. In the meantime, leafy new canes, called primocanes, grow rapidly up from between the old canes. These new canes will flower and fruit later in the summer. We thin them out and clear away those suckers that popped up around the patch. The following spring, we remove the 2-year-old canes completely to make room for new growth, cutting them off at the ground, and we trim back the 1-year-old canes. We usually top-dress our raspberry patch with well-rotted manure and berry fertilizer in early spring. You can also prune summer-fruiting varieties using this method. -finegardening