Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years and is a member of University of Hawaii Master Gardeners. Email your questions to Sakovich at askthegardenguy@earthlink.net.
Passion fruit vine won’t bear fruit
Aloha. I live in Leilani Estates and I have had a passion fruit vine for three years that has never flowered or fruited. It’s very odd, because the vine is huge and had to be cut back many times. … I’ve tried fertilizer; the vine is very healthy, no disease I can see. My neighbor’s fruits plenty. Have you ever heard of this? I’m about ready to dig it out and replant a new one. — Thanks, Cheryl
I cannot give you a definite answer to this question, but let me give you some possibilities. Pruning once a year will stimulate new growth, therefore, encouraging flower and fruit production. With overly zealous pruning, the vine will need a few years to recover. The age of the vine is a factor to consider; if the vine is very old, it may be past its prime fruit bearing years. The average life of a commercial field in Fiji is only three years. Judicious pruning can extend plantation life to 6 years. In South Africa, at elevations between 4,000 and 4,800 feet, plantings are kept in full production for as long as 8 years.
Secondly, passion fruit flowers are self-sterile, requiring the transfer of pollen. Carpenter bees are the most efficient pollinators, more than honey bees. In addition, carpenter bees will not work the flowers if the nectary in the flower is wet. When rain occurs within 11/2 hours after pollination, no fruit will set. To increase the population of carpenter bees, decaying logs can be placed near the vines to provide nesting sites for the bees. In the absence of carpenter bees, cross-pollination by hand has been successful. However, since your neighbor’s vine has plenty of fruit, I would assume that there are carpenter bees in the area. In the home garden, it is recommended that at least two vines of different sources be planted for better cross-pollination.
Transplants VS. Direct Seeding
I often receive questions about whether to plant vegetable seeds directly into the ground or plant them in small pots first, then transplant them into the garden. There are a few vegetables that need to be direct seeded, and there are a few that are best transplanted. But most vegetable plants do well either way.
In general, transplants are easier to care for. They are usually started in a more controlled environment — a greenhouse or some type of sheltered area. Here the seedlings are better protected from soil diseases, especially when a sterile potting mix and clean pots are used. A greenhouse offers protection from insects, animals digging up the ground and environmental stresses like hot winds and cold temperatures. In cooler areas, seeds can be started in a warm indoor environment earlier than direct seeding outdoors.
There is, however, a problem with transplants. Sometimes transplanted vegetables have a setback in growth so a period of time passes before they resume their growth. This is called “transplant shock” and it occurs when the transplants are set into the ground, and in the process the roots are damaged. Certain plants can regenerate new roots quickly and transplant easily: broccoli, brussel sprouts, cabbage, lettuce and tomatoes. Cauliflower, celery, eggplant, onion and peppers are slower to regenerate, but they can be successfully transplanted. The cucurbits (cucumbers, melons, squash, etc.), legumes (beans and peas) and corn have even slower root redevelopment, but if root disturbance is kept at a minimum, they will do fine.
Vegetables that have a taproot like beets, carrots and turnips should be direct seeded. Transplanting these vegetables will cause deformations and undesirable lateral root development.
Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years and is a member of University of Hawaii Master Gardeners. Email your questions to Sakovich at askthegardenguy@earthlink.net.