Growing gardens under oak trees?

Dear David,

I have 10 very mature oaks in my front 
yard. At the base of one of the oaks I have started my food forest 
experiment. I dumped a layer of compost a variety of seeds (squash, 
beans, herbs, morning glories, echinechia, passionflower and i forgot 
what else lol!) and light mulch because of the oak roots, it is growing 
good so far.  So we talked about before i would begin to stop raking 
leaves and let the leaf litter collect.  I would then have a self 
mulching landscape.  From my understanding not much will be able to grow 
as ground cover since the leaves will ultimately smother them out. I 
know i can grow vines that travel up though.  Also any fruit trees or 
bushes will be of low yield since they would only receive dappled light. 
Is the solution to just plant more?? Please tell me if what all I am 
saying is true? Also i am thinking this is a mesic oak hammock since we 
are on a lake but our house is not in a flood zone because we sit up in 
the hammock zone.  Hope that helps.

Thanks

Jennifer

I like her approach. Compost and a big mix of seeds. My kind of growing.

There are two issues here that I can see. Let’s tackle them both

1: Too Much Shade

Oaks are hard to garden under, but I hate to remove them. I explore this conundrum and my thoughts on it in my book Compost Everything in the chapter on “Stupid Worthless Trees.”

I was joking when I called them stupid worthless trees, but that’s the way many people view big, “non-productive” trees. An oak or a maple or a sweetgum is viewed as worthless by many food growers because they aren’t good sources of food. Sure, you can eat acorns or tap maples, but the work involved with processing makes them a less-than-desirable source of food.

Jennifer has a different approach. She’s letting them drop leaves and feed the soil, which large trees are great at doing. They also support other species such as birds and mushrooms – sometimes even edible mushrooms – so they’re vital parts of the ecosystem.

This edible Lactarius indigo was discovered beneath an oak tree.

The problem is the shade they create. Gardening under oaks isn’t easy unless you’re growing shade-tolerant plants. I grew grape mahonias, pineapples and gingers under mine back in North Florida. Around the edges of oaks you can also grow citrus and other fruit trees provided they get enough light. It takes a lot of solar energy to get fruit-producing vegetables like squash, tomatoes, peppers, beans, etc., to make much worth eating.

Throwing down a lot of seeds is a good idea, though – Jennifer may discover some species which are more tolerant than others of the shade.

Sometimes you can strategically remove limbs and open up the canopy to keep things growing underneath.

Planting a big variety is a good idea. The area may not be as productive as it would be without the canopy, but the oaks will buffer the overnight lows during the winter and can help you push the zone, so there are benefits.

Research shade plants for your area, test lots of species, then see what flies.

2: Leaves Covering Everything

If you are starting plants from seeds, having a lot of leaves drop can crush out young seedlings and make it hard to get things started; however, if you plant seeds when leaf drop is minimal, the plants should get established before the leaves get too thick. Older plants will be fine and the leaves will feed their roots as they grow.

One of the things I love about mature trees is how many leaves they drop. Leaves are great food for the soil and your compost pile. Perennial vegetables are easier underneath oaks, which is one reason I loved ginger. It likes the shade and will grow through leaves without trouble.

Something worth doing: travel to local parks with natural woodlands and observe what is growing beneath the oaks in wild areas. See if you can mimic what is happening in your own yard. Look for species that are edible. Smilax? Try growing its cousin asparagus. Beautyberries? Sure, plant some of those! Violets? They’re a good edible. Wild blackberries? Plant some cultivated types. See if you can find patterns in nature and then put those patterns to work in your oak gardens.

It’s not easy to grow a garden under oak trees, but it’s not impossible. Keep planting and follow your intuition and your observations.

And have fun.

*Photo credit Robert Couse-Baker. CC license.