I used to be a total mulcher, covered my whole veggie garden. I’ve adjusted my coastal SoCal mulch* thinking to match the plant! Same goes for composting in place. That’s a good idea for some areas of your garden, other areas not at all!
If you are coastal SoCal, in the marine layer zone, your mulch, or composting in place, may be slowing things down a lot more than you realize. The best melons I’ve ever seen grown at Pilgrim Terrace Community Garden were on bare hot dry soil in a plot that had a lower soil level than most of the other plots. The perimeter boards diverted any wind right over the top of the area, the soil got hot! It was like an oven! So, let it be bare! No mulch under melons, your winter squash, pumpkins except under the fruits to keep them off the ground, clean, above soil level insects.
For more heat, put up a low wind barrier – straw bales, a perimeter of densely foliated plants, a big downed log, be creative. Permeable shrubs are the most effective wind barriers. Let your peppers and jicama get hot! Eggplant are Mediterranean heat lovers! Okra is Southern, hot.
Tomatoes need dryer soil to avoid the verticillium and fusarium wilt fungi, no more than an inch of loose straw to allow airflow at soil level but keep heat down. Let ‘em dry nearby; water a foot or more away from the central stem. Let that tap-root do its job, get the water below the fungi, wilt/blight zone, the top 6 to 8 inches. Drier soil is not comfy for slugs.
Get cucumbers up on a trellis, then you won’t need mulch to keep the cukes clean and bug free, but rather because they have short roots. Preplant radish to repel cucumber beetles when your cukes bloom. The radish will provide a living mulch as their leaves shade the cuke roots. Eat a few radish, but let the rest grow out to keep repelling the beetles. In time you can gather their seeds. Plant heat tolerant lettuces at their feet to act as living mulch. They both like plenty of water to keep them growing fast and sweet, so they are great companions. Slugs and snails like peas and lettuce. You will need to use a little Sluggo or its equivalent if you feel comfortable to use it.
Clearly, no mulch, more heat, equals more water needed. In drought areas, plant in basins below the main soil level. Use your long low flow water wand to water only in the basin at the roots of your plant. Fuzzy leaved plants, tomatoes and eggplant, prefer not being watered on their leaves anyway. Since there is no raised mound, there is no maintenance needed for berms surrounding the basin, but you will need to keep the basin from filling in. Plant companion littles and fillers in the basin around the base of bigger plants. They will enjoy the cooler damper soil and provide living mulch to keep that soil more cool!
LIVING MULCH is triple productive! It mulches, provides companion plant advantages, and is a crop all at the same time! Closely planted beets, carrots, garden purslane, radish, turnips act as living mulch to themselves and bigger companion plants you plant them by. The dense canopy their leaves make lets little light in, keeps things moist. Cucumbers under broccoli are living mulch while the brocs repel cucumber beetles! If you cage or trellis your beans, most of the plant is up getting air circulation, keeping them dryer, more mildew free, if you don’t plant too densely. They, cucumbers and strawberries, also have short feet that need to stay moist, so do mulch them – your beans and cukes with clean chop and drop, straw or purchased mulch.
Zucchini, doesn’t care. They are a huge leaved plant, greedy sun lovers, that are self mulching. But, you can feed their vine up through the largest tomato cages, cut off the lower leaves and plant a family of lettuces, carrots, onions, salad bowl fixin’s or basil on the sunny side underneath! Especially preplant radish to repel cucumber beetles! All of them like plenty of water, so everyone is happy.
Cooler crops, over summering Broccoli, Kale, Chard like moist and cooler, so mulch deeply very early in spring.
Boards as mulch! Your strawberries like slightly acidic soil, and acidic mulch – redwood or pine needles. Also, you can lay down boards between mini rows of strawberries to keep the soil moist under the boards, the soil between the rows that the berry roots have access to. It’s a variation on pallet gardening. The advantages of using boards are you can space or remove your boards so you can easily access the soil to add amendments, you can add or remove boards to make a bigger or smaller patch, you can make the boards the length you need or want, space them as needed per the plant. Planting between boards can be used for lots of other plants too if you won’t be planting an understory! As for your strawberries, as they leaf out and get bigger, in addition to the boards, they will be living mulch for themselves!
If you are going to mulch, do it justice. Besides wanting to cool your soil, keep moisture in, prevent erosion, keep your crop off the soil and away from bugs, and in the long-term, feed your soil, mulching is also to prevent light germinating weed seeds from sprouting. Put on 4 to 6 inches minimum, tomatoes being the exception. Less than that may be pretty, but simply make great habitat for those little grass and weed seeds! Mulch makes moist soil, where a rich multitude of soil organisms can thrive, including great fat vigorous earthworms! You see them, you know your soil is well aerated, balanced, doing great!
Mulching is double good on slopes and hillsides. Make rock lined water-slowing ‘S’ terrace walk ways snaking along down the hillside. Cover your berms well and deeply to prevent erosion and to hold moisture when there are drying winds. Be sure to anchor your mulch in windy areas -biodegradable anchor stakes are available. Carolyn Csanyi has some clever ideas on how to keep your mulch on a slope. Plant fruit trees, your veggies on the sunny side under them, on the uphill side of your berms. Make your terrace wide enough so you don’t degrade the berms by walking on them when you harvest.
If you mulch, make it count! Mulch with an organic degradable mulch. Chop and drop disease and pest free plants to compost in place, spread dry leaves. Spread very well aged manures. When you water, it’s like compost or manure tea to the ground underneath. Lay out some seed free straw – some feed stores will let you sweep it up for free! If you don’t like the look of that, cover it with some pretty purchased mulch you like. Use redwood fiber only in areas you want to be slightly acidic, like for strawberries or blueberries.
COMPOSTING IN PLACE Build soil right where you need it. Tuck green kitchen waste out of sight under your mulch, where you will plant next. Sprinkle with a little soil if you have some to spare, that inoculates your pile with soil organisms; pour on some compost tea to add some more! Throw on some red wriggler surface feeder worms. Grow yarrow or Russian comfrey (Syphytum x uplandicum) near your compost area so you can conveniently add a few sprigs to your pile to speed decomposition. It will compost quickly, no smells, feeding your soil excellently! If you keep doing it in one place, a nice raised bed will be built there with little effort!
You don’t have to wait to plant! Pull back a planting space, add compost you have on hand or purchased, maybe mix in a little aged manure mix, worm castings, your favorite plant specific amendments. Sprinkle some mycorrhizal fungi on your transplant’s roots (exception is Brassicas), and plant! Yes!
*Mulch is when you can see distinct pieces of the original materials. Finished compost is when there are no distinct pieces left, the material is black and fluffy and smells good.
Mulch is magic when done right!
The Green Bean Connection started as correspondence for the Santa Barbara CA USA Pilgrim Terrace Community Garden. All three of Santa Barbara’s community gardens are very coastal. During late spring/summer we are often in a fog belt/marine layer most years, locally referred to as the May grays, June glooms and August fogusts. Keep that in mind compared to the microclimate niche where your veggie garden is. Bless you for being such a wonderful Earth Steward!
Love your Mother! Plant bird & bee food! Think grey water! Grow organic!