Monday, January 25, 2016

What is a cocktail tree? Grafting Different Fruit on the Same Tree

Different varieties of the same species can be grafted together. This is often done to extend the harvest period. As an example, if the Kahaluu variety of avocado were grafted onto a Sharwil avocado, the fall/winter picking season for Kahaluu would be extended into the spring by the Sharwil (winter/spring).

In addition, two varieties can be grafted on one tree in order to save space, especially, if a second variety is needed as a pollinator. In general, plants with the same genus, but of a different species, can be grafted together. Among citrus species, lemon, orange, grapefruit can be put on one tree. One word of caution, lemons are a vigorous growing tree. When lemons are put together with a slower growing citrus, care must be taken to prune the lemon graft, or else it will quickly out grow the other species.

Many deciduous fruit trees can be grafted together.  Peaches, nectarines, plums and apricots can all be harvested from one tree.

Plants belonging to different genera are less successfully grafted, although there are some cases where this is possible. For example, quince, genus Cydonia, may be used as a dwarfing rootstock for pear, genus Pyrus. Plants of different families cannot be grafted successfully, such as orange on a peach.

For more detailed information on budding and grafting avocados, citrus or deciduous fruit trees, the University of California website has excellent information:

Sunday, January 10, 2016

Crab Spiders

 Each fall local gardens are invaded by crab spiders, also known as spiny-backed spiders.  There are two species of crab spiders on the Big Island of Hawaii, both are shaped like tiny crabs approximately ½ inch across. One is white with black spots and 6 red spines. The more common one also has spines, although shorter, with two distinct white spots on its speckled yellow-brown back. In certain locations, crab spider populations increase in the fall and decline in the late spring.

These spiders are different from other spiders in their web building techniques. Their webs are interconnected, building condominiums right outside your door, under the eaves, between the shrubs and in the trees.  They seem to be spun everywhere, but the spiders are not a nuisance indoors. 

People, especially farm workers, have been bitten when the spiders fall on them or are trapped within their clothing. Females lay eggs away from their webs, on the leaves of trees and elsewhere. The egg masses look like a flat patch of fluorescent green cotton candy which turns yellow when the eggs hatch. Disposing of this egg mass will, of course, help to reduce the spider population.

Spiders, including the crab spiders, are some of the best bio-control agents known, because they feed on large quantities of insects such as aphids, ants, thrips and termites. They should be tolerated as much as possible. But, people do have their limits. A soap and/or oil solution will kill them. In addition, many household, aerosol insecticides will do a good job of killing the spiders. Before using, read the label for precautions and application sites. Note: application to plants may cause severe burning.