One of the basic necessities for an edible food forest is drawing in both the pollinators and the beneficial insects that keep the predators under control. Some folks call these insectary plants. The "friendly insects" include ladybeetles, bees, ground beetles, hoverflies, and parasitic wasps. Other animals that are frequently considered beneficial include lizards, spiders, toads, and hummingbirds.
Beneficial insects are as much as ten times more abundant in the insectary plantings area. Elimination of scale insects double with insectary plantings. Additionally, a diversity of insectary plants can increase the population of beneficial insects so much that these levels can be sustained even when the insectary plants are removed or die off.
Many members of the Apiaceae (formerly known as Umbelliferae) family are excellent insectary plants. Fennel, angelica, coriander, dill, and wild carrot all provide in great number the tiny flowers required by parasitic wasps. Various clovers, yarrow, and rue also attract parasitic and predatory insects.
Low-growing herb plants, such as thyme, rosemary and mints provide shelter for ground beetles and other beneficial insects. Composite flowers like daisy, chamomile and mints will attract predatory wasps, hoverflies, and robber flies. The wasps will catch caterpillars and grubs to feed their young, while the predatory and parasitic flies attack many kinds of insects, including leafhoppers and caterpillars.
I have many of these insectary plants (which are now big enough to be divided this year) already in my garden, but as I expand my planting areas, I need more plants I don't already have for both the new and old areas. So, I started seeds of some herbs. Not all are insectary plants, but if not, they will still attract pollinators so it's a win-win.
New herb starts include:
green shisho (perilla), which is also edible
Mrs. Burn's lemon basil
sweet basil (old seeds, not expecting anything much to germinate)
An Italian basil a friend sent 3-4 years ago, (old seeds, not expecting anything much to germinate)
lemon bee balm
I have a flat of bulbing Florence fennel I started a month ago, and last fall it looked like my dill had reseeded everywhere. The yarrow has grown enough since last spring to divide several times, as has the mint and anise hyssop.
I have chamomile seeds to start, and plenty of 2-3 varieties of shasta daisy's to divide for new guilds. My recent trip to Edible Landscaping brought me a couple of trees that can be an anchor in new guilds, but mostly I bought some fruiting vines and shrubs I wanted. I have great hopes for the fruit tree cuttings I have in mini-greenhouses but I'm not holding my breath since I'm new at rooting cuttings.
It's an adventure, for sure!