Update on planting fruit trees for pigs.

Here’s some of what I learned while trying to plant more fruit for pigs. I tried to make it somewhat of a guide for anyone interested in improving their own areas...

Plantings needed good soil to survive and thrive, so plant where other trees do well. My greatest mistakes have been planting in soil that did not provide good growing conditions. If an area is covered in dense scrub or low vegetation, it is probably junk soil. Valley floors and flats typically have the best growing conditions and, in rugged eroded country, may be the only suitable area for heavy feeders like mango, avocado, jackfruit, etc. Other areas to look for are natural shelfs along a hillside. Imagine that all the leaf little, water, nutrients, and topsoil on a hillside is slowly working its way down hill. At some point as a slope levels off, those nutrients, moisture and soil concentrate to create better growing conditions. You can often see this on a hillside by looking at how tall vegetation is. My ridge plantings have never done well. Some of you may have noticed avocados and Malabar chestnut sprouting up along powerline trail but stunting with nutrient deficiencies. Plantings in uluhe, short dense strawberry guava, and matt grasses typically failed although Nitrogen fixers like ice cream bean did have some success. Plantings along valley bottoms and flats with deeper soil typically did well.

Observations of existing trees also lent clues as to what could be planted where. For example, avocado was observed growing through and overtopping common guava stands along Hanalei river and in Hanakapiai Valley. Mango eventually grew through java plum. Macadamia was observed growing in dry hillsides in Moloa’a. Monkeypod did poor in infertile soil with stunted trees, but did exceptionally well a couple hundred yards away among taller strawberry guava. Few plants did well through haole koa, except for monkeypod and on one occasion the coastal invasive Tahitian chestnut AKA false Kamani.

Many plants can be grown from seed if the seed is placed just under the soil but those same seeds typically dried out if left in the open on top soil. Others like koa, monkeypod, and citrus were best started in pots. Larger seed plants (mango, avo, etc.) typically had enough stored energy in the seed to send a shoot up through existing ground cover and could sometimes be tossed into the ground cover where they grew through.

Pigs constantly harmed many of the seedlings causing very low success rates. Surrounding the plant or seedling with brush piles, rocks or logs significantly discouraged pigs.

Competition for light from other plants was very troublesome, especially since the best soil typically has large existing trees. Some species were shade tolerant enough to survive and shoot up through existing canopies. Others needed to be planted in light gaps and maintenance was needed until plantings could get established above the canopy. Killing existing trees standing and planting in existing light gaps proved to be the best options. Herbicide often helps, particularly with strawberry guava but was very labor and chemical intensive. The other option was to chop down the guava and keep cutting it back until plantings were established, which proved way more labor intensive. Albizia could be killed simply by girdling. Light gaps often grew back thick with weeds which sometimes crowded out plantings.

Monitoring height and taking pictures, were very useful in measuring success. I found it very encouraging, or discouraging depending on the results. An avocado planted under girdled albizia grew 8 feet in perhaps two years.

Here’s a short list of plants which I thought to have the greatest potential for improving existing pig food sources, at least on Kauai and in areas already dominated by non-native vegetation. Please note that these were chosen because of their proven hardiness and while seeming to pose no adverse risks as becoming pasture weeds, forest invaders, or noxious weeds. I left many off the list because some people might take issue with me encouraging them, such as Cainito- relative to the gum, or false kamani which is potentially invasive along streams. Many others are common already and need not worth mention here. If you think something should or shouldn’t be on the list, I’m all ears and would like to hear people’s successes and failures:

Monkeypod- seed pods & seedlings edible. Suitable for hillsides
koa -seedlings edible. Encourages earthworms. Suitable for hillsides
Icecream bean- edible fruit. Possibly suitable for hillsides.
Avocado-fruit. seasonal varieties potential for extending season.
Mango-fruit. seasonal varieties also available.
Jackfruit-fruit, nut-like seed (protein source)
Breadfruit- fruit
Malabar chestnut- nut-like seeds, protein source
Oranges, grapefruit, or citrus in general.- fruit
Macadamia- nut (protein source)

Grat job Nic! Thank you for sharing your findings! I haven't paid much attention to where they were planted but I've been checking a few Mac nut and Mango trees lately. No food yet but looking good!