Kiwi Care Guide
Kiwi, also known as Actinidia, is a wonderful, versatile fruit that thrives in various climates. Hardy kiwi (A. arguta) is particularly known for its resilience, adaptability, and the sweet, smooth-skinned fruit it produces. Below is a comprehensive care guide for growing both hardy kiwis and fuzzy kiwis, along with tips for maintaining healthy vines, ensuring proper pollination, and handling pests and diseases.
1. Types of Kiwi
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Hardy Kiwi (Actinidia arguta): These are smaller, smooth-skinned kiwis, about the size of a large grape, that can be eaten whole. They are very hardy, thrive in a wide range of climates and soil conditions, and are highly disease resistant.
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Fuzzy Kiwi (A. deliciosa): These are the larger, fuzzy kiwis commonly seen in grocery stores. They generally require somewhat warmer climates because their fruits ripen over a long season.
2. Planting Kiwi Vines
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Soil cultivation: the planting site should be lightly cultivated to keep grass and perennial weeds at a minimum. This should be done at the time of planting and throughout the vines lifespan.
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Space: Kiwi vines are vigorous and need ample space. Plant hardy kiwi vines at least 15 feet apart, and up to 20 feet apart in rows, depending on your trellis or cultivation system. The trellis should be very sturdy and built to last, as kiwi vines are long lived and can be significantly heavy in their mature years.
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Soil: Kiwi plants prefer slightly acidic, well-drained soil. While they can tolerate infertile soil, avoid planting them in poorly drained or waterlogged areas, as they are susceptible to root rot in these conditions.
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Watering: Kiwi vines are sensitive to drought, especially when young. Ensure consistent watering, but avoid waterlogged soil, which can lead to root rot. Kiwi’s fleshy roots spread from the plant in a parallel to the soil manner–they are more shallow rooted than some plants.
3. Pollination
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Kiwi vines are dioecious, meaning that male and female flowers are produced on separate plants. For fruit production, you need at least one male plant for every 5 female plants. Male plants only produce pollen, while female plants produce the fruit.
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Pollination Tip: To ensure optimal pollination and a good fruit set, plant your male and female vines within proximity (within 50 feet or so). Best spacing for the vines is about 15’ apart. This space helps maintain the trunk’s outward growing branches and limbs, and the spur-pruned one, two, and 3 year old growth fruiting areas.
4. Pruning Kiwi Vines
Kiwi vines need regular pruning to maintain structure, encourage fruit production, and manage their vigorous growth. The pruning process includes both summer and winter pruning.
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Summer Pruning:
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Rub off basal suckers to keep one trunk and cut back strong vertical growth from the canopy to keep the vine’s structure open. Vertical growth tends to shoot up quickly, so it’s important to manage it early when it's in an active growth stage.
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Spur pruning: During the growing season, pinch/prune new growth back to 4-6 inches to encourage branching and spur development. This will help develop fruiting spurs for next season. These “spurs” are usually developed for 3 years. As they age, they become less productive so a good general rule is to prune away older spurs before their 4th season.
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The practice of spur pruning new growth will typically need to be monitored and repeated as needed throughout the growing season. More mature plants will require more summer pruning than younger plants. These vines can send out new growth shoots that gain significant length in a matter of days. Staying on top of your pruning will make the task much easier and more enjoyable.
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Winter Pruning: maintains healthy 1, 2, and 3 year old spurs.
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Remove older, non-productive fruiting spurs that have completed their third season of bearing fruit.
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Cut back any weak, damaged, or tangled growth. The general idea is to manage the overall growth of the vine so that the larger limbs and smaller spurs are growing outward and getting good light and air penetration during their leafy growing season.
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Shorten long branches that could touch the ground when laden with fruit.
5. Trellis and Support Systems
Kiwi vines grow rapidly and require sturdy supports to thrive. Build a trellis before or soon after planting to accommodate the rapid growth.
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Trellis Setup:
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Use 4-6 inch diameter posts that are 8-9 feet tall, set 2-3 feet deep for stability.
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Stretch 8-12 gauge wire 6 feet above the ground for the vines to attach to.
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A “T” shaped trellis system works well for providing extra space for growth and ensuring the vines don’t become too crowded.
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Training Vines: In the first year, train the vines to grow up a stake. As the vines mature, train them to grow along the wire. Pinch back vigorous growth to encourage lateral branching. These lateral branches will produce the spurs that bear fruit.
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Tip: set your trellis north to south for less trunk exposure to the sun–this can help prevent sunscald injury to the trunk during winter.
6. Fertilization
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New Plants: When planting, avoid fertilizing excessively, as too much nitrogen can lead to excessive vegetative growth at the expense of fruit production.
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Established Plants: Apply a balanced fertilizer twice a year. Apply half before new growth begins in spring and half after fruit set in June. As plants mature, gradually increase the fertilizer amount to 3 pounds per plant by the third year.
7. Diseases and Pests
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Crown and Root Rot: One of the most serious issues for kiwi vines is Phytophthora crown and root rot. This disease is caused by waterlogged soils and can lead to plant collapse. Avoid planting in areas with poor drainage, and ensure that irrigation does not saturate the base of the plant.
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Other Pests: Kiwi vines are generally pest-resistant but may occasionally be affected by aphids, scale insects, thrips, or caterpillars. Regular monitoring and organic pest management practices can keep these pests under control.
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Japanese beetles can impede a newly planted kiwi’s growth. Monitor your plants during late spring/early summer for their presence, and control with Beetle Gone.
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Winter Protection: Fuzzy kiwis are more sensitive to winter damage than hardy kiwis. In colder regions, it may be necessary to protect the base of the vine or prune back the plant after the growing season to avoid winter die-back.
8. Harvesting Kiwi Fruit
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Maturity: Kiwi fruits mature by mid-summer, but they need the remaining season to develop their full flavor and texture. They are sweet and flavorful when ripe. In September-October, look for the first fruits that have softened within the multiple fruits on the spur. All the fruits of that spur will now ripen if picked and left off the vine at room temperature.
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Storage: You can harvest and delay ripening by storing kiwis in the refrigerator. They will soften over time, so remove them a few days before you plan to eat them to allow them to reach their peak sweetness and flavor.
9. Tips for Growing Hardy Kiwi
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Hardy kiwis are highly adaptable once established and can thrive in diverse climates. In fact, they've been successfully grown in areas ranging from Canada to Florida and west to California.
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Hardy kiwis can also be grown as landscape plants to cover walls, trellises, arbors, and even chicken coops, creating beautiful green spaces while providing fruit.
Summary
Kiwi vines, particularly the hardy kiwi (A. arguta), are an excellent choice for gardeners looking for a low-maintenance, resilient fruit that provides high yields and a unique taste. With proper care, including well-planned trellis systems, consistent pruning, and thoughtful watering and fertilization, you can enjoy a fruitful kiwi harvest for many years to come. The hardy kiwi is especially forgiving, adaptable, and suited for a wide range of climates, making it a great choice for both novice and experienced gardeners alike.