Lessons in Organic Summer Gardening from the LA Arboretum

Kimberley Stakal |

Sep 10, 2024

My summer lessons in organic gardening continued last weekend as I embarked on my second class at the Los Angeles Arboretum. This info-jammed session was all about organic gardening tips for the summer gardener. Whether you are already a master gardener or, like myself, are just starting out, there’s a cornucopia of tips I learned that are going to be very useful this season. Check out highlights from the class, including good fungus, becoming a lunatic and bananafication, right here.

The organic gardening class, taught by LA Arboretum’s staff horticulturist Jill Morganelli, was one of the best I’ve ever taken (and I used to work at Chicago’s Shedd Aquarium, where staff regularly attended “Green Training” seminars). The four-hour intensive covered the organic gardening gamut, but I’ve done my best to summarize the how-to topics for the everyday organic gardener.

Good Fungus is… Good

Mycorrhiza is fungal growth that develops at the roots of a plant in a healthy garden bed. Similar to our guts, which need beneficial bacteria for proper digestion, metabolic action and uptake of nutrients, the soil of our plants needs healthy bacteria. And just as antibiotics can kill off our beneficial bacteria, leaving our stomachs (and thus immune systems) weakened, the application of chemicals, pesticides and salts can kill the mycorrhiza in our soil, leaving our plants to become weakened. There are few instances where you should worry about the presence of mycorrhiza; they almost always connote soil health. Support your soil bacteria by using organic compost (preferably homemade).

Become a Lunatic

If you begin looking to the moon cycles for cues on when to plant what, you’ll become a more intuitive organic gardener. The moon is your best gardening friend as it tells you without any assistance the optimal times for specific gardening tasks. How is that? It’s all about gravitational pull. During the new moon, when the sky is empty, the gravitation pull is low, but as the moon moves into a full moon, it slowly becomes stronger in gravitational pull, “pulling” things from the earth up into the sky. During the new moon, you should:

Report and groom houseplants
Sow seeds of plants that grow above-ground (leafy greens, beans, tomatoes, e.g.)
Fertilize with your winter compost

And during the full moon, when the sky is glowing with light, you should get ready for the moon to drop—and when it does so, the energy begins to pull downward, back into the earth. On the full moon, you should:

Plant below-ground crops (carrots, beets, onions, e.g.)
Cultivate weeds
Plant biennials/perennials, as they need strong roots
Eliminate slugs

Bananafication

Morganelli coins the deliciously humorous term “bananafication” as a means of enriching our soils with ready-made organic compost. She started using it on her rose gardens and, after incredible success, has decided the whole world of agriculture could benefit from bananafication. It’s a 2-ingredient recipe that can be done by virtually anyone, and the results can supposedly make everything in your garden pop. To make your banana brew:

Gather 7 parts whole bananas (ripe to the point of brown) and 1 part coffee grounds (you can include the filters and all). There’s no exact science for measuring bananas and grounds, so just use handfuls to scoop.
Combine bananas and grounds in a large bucket. Using garden sheers, chop up the mixture until it’s well mashed.
Dig a hole about 6 inches under the soil around the area of your plants. It need not be a hole directly under your plants; rather, it can be a large hole next to your plot of plants, or if you’re row-cropping, make a parallel row just for burying the banana mixture.
Bury the banana mixture and cover with 6 or so inches of compost.

Give Your Plants Companions

Companion planting is a technique employed by permaculture, biodynamic and organic gardeners as a means of putting together plants that complement each other in the soil. Years ago in my zoology classes, we learned this idea as mutualistic evolution, where different species evolve together in ways that help each other survive, by means of helping them eat better, fight off enemies, fight disease and so on. This happens with animals in the wild, and it happens with plants in the garden. Permaculturists call groups of plants that should be planted together “guilds;” I call them “buddies.” Either way, here are just a few examples of plants that should be planted together for optimal growth, disease and pest repellant, and overall success:

Tomatoes, basil, marigold and mustard
Corn, beans, peanuts and pumpkins
Peppers, lettuce, celery, melon and pyrethrum
Carrots, onions, rosemary, tomatoes and leeks
Cucumber, sunflower, peas and dill
Fruit trees, lavender, chives, strawberries, mint and comfrey
Tomatoes, parsley and sage

… From a culinary perspective, I’d love to note that the guilds of companion plants happen to be plants that are also used together in common cuisines around the world, such as tomatoes, basil and mustard, or corn, beans and pumpkins. They also happen to be nutritionally complimentary, such as corn and beans, which make a complete vegetarian protein together. What’s nutritious together is also delicious together is also grown together—it’s all connected.

Getting Rid of the Bad Guys

Arguably the hardest part of organic gardening successfully is dealing with the pests and diseases that invade our crops. But by identifying the deeper root (no pun intended) of the cause of infestation, we can help to heal our plants, rather than just treat them with chemicals, as conventional agriculture does. Again, think of it like our stomachs (or entire bodies), which become ill with disease from improper nutrition or care. Rather than treat the condition with hard medication, we can often help from the inside out with better nutrition, care and remedies. Here are just a few examples for your plants:

Slugs: Oak leaves are the perfect pH for healthy soil, and they promote earthworms in the soil, which will kill slugs off. Add ground or torn oak leaves just to the topsoil of your crop, and wear gloves, as they are prickly! Coffee grounds also deter slugs from wanting to traipse over the soil of your garden, so sprinkle it over the topsoil.
Tomato Verticillium Wilt (marked by funky, brow, wilty leaves): This usually only occurs to tomatoes late in the season, when they’re ready to be harvested, and it shouldn’t affect the growth of your tomatoes, so don’t worry too much about this one. Let it be, Paul.
Tomato Black Mold: In general, buy an heirloom cultivar that’s resistant to this disease. But if your tomatoes get it, it shows they aren’t getting enough air and circulation in the soil. Keep them well spaced and don’t overwater them.
Spittle Bug: These foam-spraying bugs are virtually harmless to your plants, but they can be pesky. Hose them off gently to get rid of them.
Wooly Bear Caterpillar: These leave-destroying caterpillars love herbs and kale. Use BT or Spinocid (two natural applications) on the leaves to deter them, or simply hand-pick them off with your fingers.
Tomato Hornworm: This critter makes your tomatoes into skeletons and leaves giant droppings. One remedy is to take one of the bugs, blend it with water, and spray it onto the plant; it is supposed to deter others.

Small Spaces

Being that so many of us live in urban environments and small spaces, Morganelli gave several tips on gardening with what you’ve got, taken from permaculture and biodynamic friends of hers in the business. It’s all about reusing old materials from the household, provided they are free of toxic paints or other chemicals and have ample drainage (that’s what nails are for!). Here are just a few crafty ways to fashion an organic garden from scratch:

Use old wooden barrels as planters. If the bottoms have no drainage already, drain multiple holes with nails or a drill.
Take old drawer shelves and nail them upright on a diagonal within long wooden planks, giving you long, stacked wooden beds that can stand upright against the side of a house, patio or apartment door.
Nail old gutters along the wooden siding of a house or apartment in horizontal rows; you can get several long rows of planters this way!
For more resources, check out www.gardeninginsmallspaces.com

To Be Continued

The next organic gardening class is offered at the start of fall and will offer gardeners tips on getting ready to plant their fall harvest crops, making compost and all things winter gardening. It’s taught by the same fabulous horticulturist, Jill Morganelli, and should prove to be another informative class. If you’re in the Los Angeles region, I highly recommend these classes. Learn more here: Los Angeles County Arboretum and Botanic Garden.

Image: stevendepolo