Kiwi plants, part of the Actinidia genus, originate from the mountainous regions of southwestern China. While the specific origins within China may differ among species, their primary ancestral home is undeniably China.
Kiwi plants thrive in a wide range of climates, from cooler to warmer regions. These versatile plants produce delicious and nutritious fruits, making them a rewarding addition to any home garden.
Types of Kiwi Vines
There are two primary types of kiwi plants suitable for home gardens: kiwifruit and kiwi berry. Both require frost-free conditions and thrive in regions with a minimum of 200 frost-free days.
1.) Kiwifruit (Actinidia deliciosa)
The fuzzy brown kiwifruit you are familiar with is scientifically known as Actinidia deliciosa. It is usually around the size of an extra-large chicken egg. You can purchase these fruits from grocery stores or fruit specialty shops. Kiwifruits thrive in warm climates, specifically in USDA zones 8 to 9.
Kiwifruit plants have their origins in southern China. The United States, Europe, and New Zealand imported these plants from southern China in the early 20th century. Since then, New Zealand has been producing these fruits in large quantities and is now the world’s leading producer.
2.) Kiwiberry (Acinidia arguta)
Björn Appel, Weiki01, CC BY-SA 3.0
Kiwiberry (Actinidia arguta) is a vine that bears small, smooth, green fruit resembling grapes. These plants are Indigenous to Japan, China, and Korea. This adaptable plant is commonly known as “Hardy kiwi” or “Northern kiwi.”
As its name implies, the hardy kiwi (Actinidia arguta) thrives in colder regions (USDA zones 4 to 7) and can even withstand subzero temperatures. Gardeners often cultivate these plants for their ornamental values. They boast pink-variegated leaves and fragrant blooms.
Varieties of Kiwi Vines
Kiwi Fruit
Kiwi fruit’s (Actinidia deliciosa) main female variety is ‘Hayward’. Commercial growers cultivate this variety on a large scale. It has fuzzy brown skin and delicious green interior pulp. You can find them commonly in grocery stores worldwide.
Male Varieties include ‘Matua’, ‘Tamori’, and ‘Chico’.
Kiwi Berries
1.) The self-fertile Actinidia arguta ‘Issai’ produces an abundance of small, juicy fruit without the need for a male pollinator. Its fragrant white blossoms, which bloom in early summer, are a favorite among pollinators.
2.) The Actinidia arguta ‘Ananasnaya’, also known as ‘Anna’, boasts a jade-colored skin (mostly rich, emerald green) color, bright green pulp, black seeds, and a delightful pineapple flavor.
3.) Actinidia arguta ‘Geneva’ ripens earlier than both ‘Anna’ and ‘Issai’, offering sweet, honey-like fruit.
4.) Actinidia kolomikta ‘Red Beauty’ offers an early harvest compared to most hardy kiwi varieties, though it can be more challenging to cultivate. This vine produces slender, sweet fruit and delivers a stunning display of crimson (brilliant red) foliage in autumn.
5.) Actinidia arguta ‘Ken’s Red’ is distinguished by its fruit with a striking reddish-purple skin. The interior flesh is dark green in color, accented with deep red streaks.
Growing Kiwi Vines
Photo by A.j.morris (CC BY-SA 3.0)
Plant kiwi vines in the spring once the danger of frost has passed. Patience is key, as kiwi vines typically begin producing fruit three to five years after planting.
Sunlight
Kiwi vines thrive in sunny environments, which are essential for their growth and fruit production. Plant them in a sheltered spot to shield them from damaging winds. In colder climates, consider planting them on the north side of your yard to minimize the risk of frost damage, particularly vulnerable in early spring.
Some variegated kiwi varieties exhibit their most vibrant and striking color patterns when grown in full sunlight. Lack of sufficient light can cause the foliage to become dull and the variegation to be less distinct.
Soil
Kiwi plants thrive best in loamy, rich, and well-drained soil (pH range of 5.0 to 6.8), as they are susceptible to root rot if the soil remains too wet.
To ensure optimal growth, it is beneficial to amend garden beds with organic matter such as compost or manure. This not only enhances soil fertility but also improves drainage, providing the ideal environment for vining fruits to flourish.
Other Requirements
Trellis
Kiwi vines grow slowly and require robust support structures. It is essential to set up a tall, heavy-duty trellis system capable of supporting vines that can spread up to 15 feet in width and 20 feet in length. These vines can yield up to 100 pounds of fruit.
Planting
To bear fruit, both male and female kiwi plants are necessary. While the male plant produces pollen-bearing flowers, the female plant develops both flowers and the coveted fruit.
For optimal fruit production, it is recommended to plant at least one male kiwi vine for every six female vines. Space them 10 to 15 feet apart for adequate growth. However, if space is limited, consider the ‘Issai’ variety of hardy kiwi, known for its self-fertility.
Propagating Kiwi Vines
Klingon, Kiwifruit-Actinidia deliciosa-plantation, CC BY-SA 3.0
The preferred method for propagating hardy kiwi is from cuttings. This technique guarantees that the new plant will have the same sex as the parent. Gardeners aiming to grow kiwi for fruit can easily choose both male and female cuttings if they already know the sex of the parent plants.
Propagation from Cuttings
Propagating kiwi vines from cuttings is a relatively straightforward process. Here is a basic guide:
1.) In summer, select a tender, new growth (softwood cutting) measuring 5 to 8 inches in length and about half an inch thick. Sever the branch directly below a leaf, creating a clean cut.
2.) Remove the leaves from the lower half of the cutting, leaving only a few sets at the top.
3.) Dip the base of the cutting into the rooting hormone, ensuring even coverage.
4.) Fill small pots having drainage holes with potting mix. You can also use rooting trays for this purpose.
5.) Create a hole in the moist potting mix using your finger or a pencil. Insert the bottom inch of the cutting into the hole and gently firm the soil around it.
6.) Thoroughly water the potted cutting, allowing excess water to drain completely.
7.) Place the pot in a warm, sunny indoor environment, ideally a greenhouse, to encourage root development.
Rooting should occur in six to eight weeks. As your cutting grows about 4 feet in height, harden it off and transplant it outdoors.
Propagation from Seeds
Many gardeners prefer not to grow kiwi vines from seed, particularly if they aim to harvest fruit. This is because growing from seed does not guarantee the sex of the resulting plant. However, if you are interested in a beautiful vining foliage plant, you can still grow hardy kiwi from seed, provided you are prepared to replicate the necessary stratification conditions.
1.) Extract the seeds from a ripe kiwi and allow them to dry for two days.
2.) Place the dried seeds in a container filled with damp perlite. Store the container in the refrigerator at a consistent temperature of 40°F (4°C) for a period of two months.
3.) Fill a pot with moist, sterile potting mix. Gently press the prepared kiwi seeds about 1/8 inch deep into it. You can also cover the container arrangement with plastic wrap to maintain humidity.
4.) Place the pot arrangement in a warm, sunny location and keep the soil consistently damp. You can remove the plastic wrap as the seedlings start to grow.
5.) Once seedlings develop four true leaves, carefully transplant them into individual pots. When the plants have grown several inches tall and the weather is consistently warm, they can be transplanted outdoors.
Caring Kiwi Vines
Water
Ensure the soil around your new kiwi plants remains consistently moist until it is well-established. They need at least one inch of rainfall about every 10 days, particularly right after planting. If your climate meets this requirement, additional watering is usually not required. During dry spells or in arid climates, water every week. Providing about one gallon of water per plant through drip irrigation should suffice
Fertilizer
This vigorous vine requires a lot of nitrogen, so be sure to supply enough nutrients. Avoid fertilizing during the first year. However, you can start fertilizing every spring from the next year.
Feed your kiwi plants three inches of compost at their base to provide essential nutrients for the growing season. Choose from organic options like aged manure, aged mushroom compost, or a blend of rotted pine bark and aged manure. Alternatively, you can use a soybean meal or balanced fertilizer.
Pruning
For optimal fruit production, prune kiwi vines in winter. During the first year, choose the most vigorous and straight shoot to establish as the permanent trunk, cutting back the others to concentrate growth in the trunk. During the summer, prune as needed to remove excessively overgrown or long shoots. Before winter, trim the stems, leaving only about 8 to 10 nodes on them.
Overwintering
Many varieties of Kiwi veins, especially of the hardy kiwi plants can tolerate temperatures as low as -25°F, but protecting them is crucial for optimal fruit production. Young vines require minimal winter care. Just wrapping the trunks around with frost protection or piling soil and leaves around the base will suffice.
After overwintering a few years, your plant should become resilient enough to endure cold temperatures without additional care. In the spring, be sure to shield new shoots from late-season frosts using a blanket or cover, as hardy kiwi produce fruit on the current season’s growth. Any harm to this growth can impact your harvest.
Common Pests and Diseases in Kiwi Veins
Kiwi vines are vulnerable to several pests, including:
Two-spotted spider mites: These small pests can cause stippling and yellowing of leaves. You can use horticultural oil to control them.
Japanese beetles: Although not considered as pests in some parts of the world including Japan, can heavily damage fruits and skeletonize leaves of your kiwi plants. You can just hand-pick them or control them using insecticides.
Leafrollers: These types of caterpillars can damage both the fruit and foliage of plants. You can use Bacillus thuringiensis (Bt) or common insecticidal soaps to control them
Thrips: These minute insects, with their asymmetrical mouthparts, can cause leaf damage and stunted growth. You can treat them with good-quality neem oil or insecticidal soap.
Kiwi vines are also susceptible to several diseases, including:
Root rot: This is a fungal disease that can damage roots. You can prevent it by avoiding overwatering and planting in well-draining soils.
Anthracnose: This is a fungal disease that can lead to brown spots on both fruits and leaves. Prevention includes avoiding overhead watering and practicing good sanitation
Crown rot: This is a fungal disease that causes wilting and eventually dieback of plant branches. Prevention includes avoiding over-fertilization, planting in well-draining soils, and providing sufficient ventilation.
Bacterial canker: This is a bacterial disease that can lead to sunken cankers on trunks and branches. You can prevent it by practicing good sanitation and avoiding mechanical damage to your plants.
Harvesting and Storing Kiwi Fruit
Your kiwi vines will reward your care with a delicious harvest. Kiwis are ripe and ready to pick when they feel soft to the touch and release a sweet fragrance. It is important to wait until they are fully mature on the vine, as they won’t continue to ripen after picking.
To harvest your kiwi fruits, gently twist the fruit from the vine or carefully cut the stem with a sterilized sharp knife. Handle both the fruit and vine with care, as they are delicate and easily damaged. You can enjoy them fresh or store them in the refrigerator for up to six weeks.
If you intend to store kiwi fruits, it is ideal to harvest them just before they fully ripen.
Kiwis typically mature in September or October, which can coincide with early fall frosts in some regions. If frost threatens, harvest kiwis while they are still firm but have developed black seeds.
You can store Kiwi fruits in the refrigerator safely for up to six weeks. After that, they begin to change their characteristics. Before consuming, you can soften them by taking them out of the refrigerator and storing them at room temperature for 1 or 2 days.
Cooking Notes
Raw kiwifruits are rich in protein-dissolving enzymes called actinidain. This makes them unsuitable to use in dishes that contain gelatin or milk products. If not served immediately, the enzyme begins to break down the proteins in these dishes, ruining their texture.
Especially in gelatin-based dishes, these enzymes can inhibit the liquid from solidifying. Therefore, it is essential to consider these factors when using kiwifruit in your dishes.
Frequently Asked Questions
Kiwi trees start bearing fruit 3-5 years after successful planting. Regular caring such as adequate watering, pruning, fertilizing, etc., along with other factors may speed up fruiting a bit.
To ensure a bountiful kiwi harvest, you’ll need both male and female plants. While female vines produce delicious fruit, male plants are essential for pollination. A general rule of thumb is to plant at least one male plant for every six female vines.
While growing kiwis isn’t overly complex, it does require careful planning and consistent attention. Given their impressive size—vines can reach 20 to 30 feet in length and width—sturdy support structures are essential.
Hardy kiwis are more cold-tolerant than their tropical counterparts but remain vulnerable to early spring frosts. To protect your vines, select a planting spot shielded from cold winds and frost pockets. Strong winds can also damage the vines, so a sheltered location is ideal.
Optimal growing conditions for kiwis vary based on climate. In cooler regions, planting against a sunny, sheltered south or west-facing wall is ideal. Alternatively, growing under cover is beneficial. Warmer climates favor full sun exposure, but it’s crucial to provide shade for the roots during the hottest part of the day.
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