You may think that vines and groundcover plants are pretty interchangeable, and they can share a similar role. However, as we covered in the Plant Guild #6: Groundcovers these plants do not have to vine, but just cover large spaces close to the ground and coming from a single trunk or stem.
Vines can be large and heavy, small and delicate, perennial or annual. In a food plant guild vines are often food-bearing, such as squash. If you recall the legendary Three Sisters of planting – corn, beans and squash – there are two vines at work here. The corn forms a trellis for the light and grabby bean plant to climb upon (the bean fixing nitrogen in the soil as well as attracting pollinators with its flowers). The squash forms a low canopy all around the planted area. The big leaves keep moisture in, soften the raindrops to prevent erosion and deoxygenation, drop leaves to fertilize the soil, provide a large food crop, and attract larger pollinators. Even more than that, the squash protects the corn from raccoons. These masked thieves can destroy an entire backyard corn crop in a night, just when the corn is ripe. However, they don’t like walking where they can’t see the ground, so the dense squash groundcover helps keep them away.
Vines are very important to use on vertical space, especially on trees. With global warming many areas now have extremely hot to scorching sun, and for longer periods. Intense sun will scorch bark on tender trees, especially young ones. By growing annual vines up the trees you are helping shade the trunk while producing a crop, and if the vines are legumes you are also adding nitrogen fertilizer.
Be sure the weight of the mature vine isn’t more than the tree support can hold, or that the vine is so strong that it will wind its way around new growth and choke it. Peas, beans and sweetpeas are wonderful for small and weaker trees. When the vines die they can be added to the mulch around the base of the tree, and the tree will receive winter sunlight. When we plant trees, we pop a bunch of vining pea (cool weather) or bean (warm weather) seeds right around the trunk. Larger, thicker trees can support tomatoes, cucumbers, melons, and squash of various sizes, as well as gourds. Think about how to pick what is up there! We allowed a alcayota squash to grow up a sycamore to see what would happen, and there was a fifteen pound squash hanging twelve feet above the pathway until it came down in a heavy wind!
Nature uses vertical spaces for vines in mutually beneficial circumstances all the time, except for notable strangler vines. For instance in Southern California we have a wild grape known as Roger’s Red which grows in the understory of California Live Oaks. A few years ago there appeared in our local paper articles declaiming the vines, saying that everyone should cut them down because they were growing up and over the canopy of the oaks and killing them. The real problem was that the oaks were ill due to water issues, or beetle, or compaction, and had been losing leaves. The grape headed for the sun, of course, and spread around the top of the trees. The overgrowth of the grape wasn’t the cause of the problem, but a symptom of a greater illness with the oaks.
Some vines are not only perennial, but very long-lived and should be placed where they’ll be happiest and do the most good. Kiwi vines broaden their trunks over time and with support under their fruiting stems can be wonderful living shade structures. A restaurant in Corvallis, Oregon has one such beauty on their back patio. There is something wonderful about sitting in the protection of a living thing.
Passionvines can grow up large trees where they can receive a lot of light. Their fruit will drop to the ground when ripe. The vines aren’t deciduous, so the tree would be one where the vine coverage won’t hurt the trunk.
Vines such as hops will reroot and spread wherever they want, so consider this trait if you plant them. Because the hops need hand harvesting and the vines grow very long, it is probably best to put them on a structure such as a fence so you can easily harvest them.
So consider vines as another important tool in your toolbox of plants that help make a community of plants succeed.
Next in the Plant Guild series, the last component, Insectiaries. You can find the entire 9-part Plant Guild series here: Plant Guilds: What are they and how do they work? The first in a series. , Plant Guild #2: Canopy , Plant Guild #3: Sub-Canopy , Plant Guild #4: Nitrogen-Fixers, Plant Guild #5: Mining Plants, Plant Guild #6: Groundcovers, Plant Guild #8: Insectiaries, Plant Guild #9: The Whole Picture.