You should fertilize kiwi twice a year for best results in most growing situations. Apply the first dose in early spring when buds start to swell and the second in early summer around June. These two feedings give your vines steady nutrition through their active growth period without pushing late season growth.
Your kiwi fertilizer schedule needs to change as your vines get bigger and start making fruit. A first year plant needs just 1.5 ounces of 10-10-10 spread in a ring around the base. By year five you should be giving 1-1.5 pounds per vine each season. The amounts go up because bigger vines with more leaves and fruit need more food.
I learned to watch leaf color as my guide for feeding kiwi plants at the right rate. Healthy leaves stay dark green all summer. When I see leaves turning pale green or yellow between the veins my vines are telling me they need more nitrogen. That color change shows up about two weeks before growth starts to slow down.
Kiwi are heavy feeders that pull lots of nitrogen from the soil to build their vines and fruit. Young plants use nutrients to grow canes and leaves. Once they start fruiting they need even more since each fruit pulls resources from the vine. A mature plant making 50 pounds of fruit needs a lot more food than a young vine still getting going.
Stop all feeding by mid July no matter how tempting it is to push more growth. Late season fertilizer causes new shoots to grow that will not harden off before frost. Those soft canes die back in winter and can let cold damage into the main vine. Let your plants rest and prepare for dormancy in late summer.
Spread fertilizer in a ring starting about 6 inches from the trunk out to the drip line where leaves reach. This puts food where the feeder roots grow rather than right against the stem. Water well after you apply so nutrients soak down into the root zone fast. Dry fertilizer sitting on soil takes longer to work.
Organic growers can fertilize kiwi with compost or aged manure instead of store bought blends. Apply 2-4 inches of compost around vines each spring for slow release feeding all season. Add extra nitrogen from blood meal if your leaves look pale. Compost alone may not give enough food for heavy feeders like kiwi.
I switched to organic feeding three years ago and my vines took a season to adjust. Now they produce just as much fruit as when I used synthetic fertilizer. The key was adding blood meal each spring to boost nitrogen levels. Watch your leaves and adjust your feeding based on what your plants tell you through their color and growth rate.
Read the full article: Growing Kiwi: Expert Plan for Home Gardeners
