Posts tagged crop

Spring pruning tips

Richard Jauron, extension horticulturist at Iowa State University, offers the following on spring pruning of berries and other small fruits:

Small fruits that are commonly grown in home gardens include raspberries, grapes, gooseberries, currants and blueberries. For maximum production, small fruit crops need to be pruned in late winter/early spring (March/early April). Proper pruning procedures for raspberries, grapes, gooseberries, currants and blueberries are outlined below.

Raspberries
The pruning procedures for raspberries are based on the growth and fruiting characteristics of the plants.

Summer-Bearing Red Raspberries
Remove all weak, diseased and damaged canes at ground level in March or early April. Leave the most vigorous canes, those approximately 1/4 inch in diameter when measured 30 inches from the ground. After thinning, remaining canes should be spaced about 6 inches apart.

Also, prune out the tips of the canes that have died due to winter injury. Cut back to live tissue. If the canes sustained little winter dieback, remove the top 1/4 of the canes. Cane-tip removal or “heading-back” prevents the canes from becoming top heavy and bending over under the weight of the crop.

Red raspberries sucker profusely from their roots. Plants should be maintained in a one- to two-foot-wide hedgerow using a rototiller or spade. Remove or destroy those shoots that emerge outside the one- to two-foot-wide hedgerow.

Fall-Bearing Red Raspberries (Two Crop System)
Follow the same pruning procedures as described for the summer-bearing red raspberries. This pruning option provides both a summer and fall crop.

Fall-Bearing Red Raspberries (One Crop System)
Prune all canes back to ground level in March or early April. While the plants won’t produce a summer crop, the late summer/early fall crop should mature one to two weeks earlier. Also, total crop yield is typically larger using the one-crop system versus the two-crop system.

Maintain the plants in a one- to two-foot-wide hedgerow.

Black and Purple Raspberries
Remove the small, weak canes, leaving only four or five of the largest, most vigorous canes per clump or plant. Cut back the lateral (side) branches to 12 inches in length for black raspberries and 18 inches for purple raspberries.

Grapes
Grapevines produce fruit clusters on the previous season’s growth. Before pruning, a grapevine may have 200 to 300 buds capable of producing fruit. If the vine is not pruned, the number of grape clusters would be excessive and the grapevine would be unable to ripen the large crop or produce adequate vegetative growth.

To maximize crop yields, grapevines are trained to a specific system. The most common training system used by home gardeners is the four-cane Kniffin system. The four-cane Kniffin system is popular because of its simplicity. In the four-cane Kniffin system, the canes of the grapevine grow on two wires, one located three feet above the ground and the second six feet high.

If using the four-cane Kniffin system, select four canes on the upper wire, two going in each direction. Also, select four canes on the lower wire. To aid identification, some gardeners tie brightly colored ribbons or strips of cloth on those canes they wish to retain. All remaining one-year-old canes should be completely removed.

Going back to the upper wire, select two of the remaining four canes (one going in each direction). Prune these canes back to one or two buds. These short one or two bud canes are referred to as renewal spurs. The renewal spurs provide the shoots or canes that will produce next year’s crop. Prune the remaining two canes on the upper wire back to eight to 13 buds. The number of buds left on the fruiting canes is determined by plant vigor. If the grapevine is vigorous, leave 13 buds per cane. Leave only eight buds per cane if the grapevine possesses poor vigor.

Prune the four canes on the lower wire the same as those on the upper wire. When pruning is complete, no more than 60 buds should remain on the grapevine. When counting the number of buds on the grapevine, include both the buds on the fruiting canes and those on the renewal spurs.

Gooseberries and Currants
Gooseberries and currants produce the majority of their fruit on 2- and 3-year-old shoots. Shoots that are 4 years old and older produce very little fruit. After the first growing season, remove all but six to eight vigorous, healthy shoots. The following year, leave four or five 1-year-old shoots and three or four 2-year-old canes. After the third growing season, keep three or four shoots each of 1-, 2-, and 3-year-old growth. A properly pruned, established plant should consist of nine to 12 shoots. Pruning of mature plants consists of pruning out all 4-year-old shoots and thinning out some of the new growth.

Blueberries
Blueberry plants are shrubs like currants and gooseberries. Blueberry yields and fruit quality decline when blueberry shoots (stems) reach 5 years of age. In late winter/early spring, prune out any dead or diseased stems. Also, prune out stems that are 5 years old and older. Allow one to two new shoots to develop each year.

The pruning of small fruits really isn’t difficult. It requires a basic understanding of plant growth and pruning techniques, proper pruning equipment and (sometimes) a little bit of courage.

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Lost strawberry season?

Just days before the Iowa floods, I talked to a local grower who was expecting a bumper crop this year. Since then, I haven’t been able to reach him, but it sounds like his was among the many areas flooded out in mid-June. I didn’t see much in the way of strawberries at our local markets, either.

 

If you were lucky enough to have homegrown strawberries this year, Richard Jauron, Horticulture Specialist at Iowa State University Extension, offers some tips, noting that now is the time to tend to June-bearing strawberry beds to ensure a good fruit crop next year:

  

A June-bearing strawberry planting can be productive for several years if the bed is given good care. One important task is to renovate June-bearing strawberries immediately after harvest. The renovation process involves leaf removal, creation of 8-inch-wide plant strips, and fertilization. After the initial renovation steps have been completed, irrigation and weed control are necessary throughout the remainder of the growing season.

 

Start the renovation of June-bearing strawberries by mowing off the leaves 1 inch above the crowns of the plants with a rotary mower within one week of the last harvest. (Do not mow the strawberry bed after this one week period, as later mowing destroys new leaf growth.) To aid in disease control, rake up the leaf debris and remove it from the area.

 

June-bearing strawberries grown in 2-foot-wide matted rows should be narrowed to 8-inch-wide strips with a rototiller or hoe. When selecting the part of the row to keep, try to save the younger plants and remove the older plants. If the strawberry planting has been allowed to become a solid mat several feet wide, renovate the bed by creating 8-inch-wide plant strips. Space the plant strips about 3 feet apart.

 

Fertilization is the next step in renovation. Apply approximately 5 pounds of 10-10-10 or a similar analysis fertilizer per 100 feet of row to encourage plant growth and development.

 

Water the strawberry plants during hot, dry weather. Strawberries require approximately 1 inch of water per week for adequate growth. Irrigate the planting during hot, dry summer weather to ensure optimum production next season. Irrigation during the summer months encourages runner formation and flower bud development. (The flower buds on June-bearing strawberries develop in late summer and early fall.)

 

Control weeds in the strawberry planting by cultivating and hand pulling.

 

Some June-bearing strawberry varieties are extremely vigorous, producing runners beyond the 2-foot-wide matted row. These runners should be placed back within the 2-foot row or removed to prevent the planting from becoming a solid mat of plants.

 

Well-maintained strawberry plantings that are renovated annually may remain productive for four or five years. Poorly managed beds may be productive for only two or three years.

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