The Wicking Beds: One month on.

Hello there. It's now mid-May and the beds have been active for about a month. May has been a really variable month in terms of weather. 60s and rain one day, high 80s and bright sun the next.

My hubby and I later re-built the shade on this box with a 30% shade cloth rather than scraps of weed cloth. I had two patches of red-veined sorrel in the front, but they really didn't like the bright sunlight and heat, so I moved them to another box.  The alyssum in front is wilting and shriveling. The Lollo rosso lettuce wilts daily, and I'm sure I'm going to come home to desiccated leaves one day soon.  They don't have deep roots yet. This is an example of how the soil in a peat-mix bed has inconsistent moisture. The soil around the alyssum (front), Lollo rosso (exact center), and in the back by the peppers (just over the cat's back) shows low moisture level. Four inches from any one of these spots, and the meter reads moist

The blackberries. The one on the left took a bit longer to take off. But it seems happy in the sub-irrigated planter.  I ran out of mulch, but in eventually had about a 3 inch layer on it. 

Blueberries, a high bush variety. Planted too late for berries this year, but I should get a few next year. 

Nasturtiums, because they are happy flowers. 

The "rookie mistake" planters. These are the clear plastic ones that grew algae. The black plastic blocked the light, and all the algae died. I planted garlic that had sprouted in my fridge, kale, and arugula. The heat is hard on these seedlings. 

Anyone know what this plant is, the one with the varigated border? It came is a mystery pack of greens I got on clearance. It's pretty and tasty. 

This one finally got big enough to identify as Kolrabi. The aphids think it's about the tastiest thing ever. 

Not all soil is created equal.

When you're building large planter boxes, you have to think about what kind of soil to put in it.

Using soil from the garden is likely a bad idea. You'll be transplanting weeds and possibly diseases into your boxes. And you may have to augment the soil to get the nutrition levels up. But what should you put in those shiny new boxes?

I did my first couple of boxes with the soil mix recommended in the All New Square Foot Gardening book, by Mel Bartholomew; 1 part compost, 1 part peat moss, and 1 part vermiculite or perlite. 

Compost: be careful where you get this. If you're buying it in the bag, read the labels carefully, and make sure it's organic. If you don't, it's possible you will get a compost that has been treated with a chemical that inhibits seed germination or herbicides. Keeps the weeds down, but it makes it hard for your own seed to germinate. Not exactly what you want for your garden. I bought 1.5 cubic yards of compost from a local nursery. It looked and smelled like fantastic compost. But I didn't ask if it was organic before ordering it, and many of my seeds didn't germinate (arugula, peas and beans), and my tomato plants developed a weird leaf curl that doesn't look like anything associated with diseases (the leaves themselves curled under and down, making only the leaves look like a shepherd's crook.)

Peat moss vs Coconut Coir: Skip the peat moss. It's not renewable and it doesn't wick moisture very well. It may hold moisture in a traditional top down irrigated bed, but for the sub-irrigated planters where I used peat, I have inconsistent moisture levels in the bed. The later wicking beds that I made with Coconut coir are far superior; moist without being damp, consistent moisture throughout the day, even when it's 104F outside (like today). The plants in coconut coir/compost mixture don't wilt in the hot of the day, and the peat-mix plants do. Coconut coir is by far superior.

Vermiculite/perlite: Slightly different products which do about the same thing. They are lightweight puffy stone bits the supposedly aerate the soil. I'm kind of at a loss why this would be important in a sub irrigated planter. It seems like these airy bits would interfere with the wicking process. In fact, I used the 1:1:1 mixture in the first bed. This may be part of the reason that my first bed isn't quite as healthy as later beds. In later beds, the mixture was more like 2 parts compost: 1 part coir: 1/8 part perlite. In the future, I'm not going to add perlite for aeration. I'm going to do it a better way. Worms.

Worms: RobBob talks a fair bit about worms. He makes sure he's got a mix of them in each bed. As you mulch the top of the beds, the worms nibble it down and poop nutrition for the plants. Their burrowing also keeps the soil light and aerated. It's going to be worms and not perlite for me from now on. Just remember to keep feeding your worms by mulching your beds. You can also make worm feeding stations, and fill them with ground up veggies.

Sub-irrigated planters, a.k.a. Wicking beds: a Beginner's Tale

We live in California's Central Valley, and we've been brutalized by drought for the last several years. Add to that, the winters are getting warmer and the summers hotter. I like to garden, but I put it on hold the last few years while I finished grad school (MS with honors, UCSF class of 2015, thank you very much). I also wanted to find a better way to garden for my region. 

The traditional methods I was raised with are very water intensive. Often, I would be watering twice a day, to keep ahead of evaporation. The rest of the water would percolate down through the soil, and below the level needed for my plants. I knew that in my drought plagued area, I had to find a better way. 

My investigations led me to AlboPepper, OneYardRevolution, and later to RobBob on YouTube. I also learned about the Square Foot Gardening method and how it can make gardening easier, more productive, and more fun. With these intrepid urban gardeners as my teachers, I began studying sub-irrigated planters (aka wicking beds), soil composition, and permaculture. 

In mid-April, the hubster and I built our very first sub-irrigated planter. We used a plan very similar to AlboPepper's. 

It's a 9'x3' raised bed made from scrap lumber. It's about 16" tall. We filled the bottom of the box with sand to make sure the base under the liner was level.

Then, we lined to box with pond liner (got a deal on it on Amazon). And laid corrugated, perforated drain pipe in the bottom (capped the ends of the pipe with weed cloth and duct tape to keep the soil out). 

And filled the box with soil using the mix recommended by Mel Bartholomew. 

And planted! Nasturtiums, Alyssum, Salvia, Marigold, Basil, Catnip, Arugula, Red Lettuce, Red veined sorrel, Mystery mixed greens, Chives, Tomatoes, Pasilla chilies, Ghost chilies, and Peas. 

We made several rookie mistakes while building that planter. 

1. The liner in the box has no slack in the bottom. We folded it all nice and neat, and stapled it in place, laid the pipe, filled it with soil, and then filled the resevoir with water. All that weight (about a 1 ton) made the liner stretch a bit. It didn't cause any tearing, but on later planters we left more slack in the bottom, and left the stapling until the box was full. 

2. We didn't check for water leaks before filling it with soil. You'd think it would be a no-brainer, but we were so excited to get to planting, it didn't occur to us to check. And yes, we had a leak around the overflow pipe, so we had to dig out the soil and patch it. 

3. I didn't top water the soil before planting it. Over the next week after planting, the soil settled. What was once a nearly full planter, is now more than 4 inches below the top of the box. This places the top of the soil a mere 8 inches above the reservoir. I think that is going to be too short of a distance for some of the bigger plants that I put in. My plan is to gently back fill with mulch. 

4. Waiting until April to plant. Spring is a slow blink here in the 9b, and now we're on to summer. Some of the plants (lettuces) that hate heat are not going to make it to July I think. I was hoping to let them go to seed and replant for next year. I missed blueberry and blackberry harvests because I waited to start this project, too. 

Good advice: 

1. Use as much donated and scrap material as you can. If you don't, the project could get really expensive really quickly. 

2. Cover the ends of the corrugated-perforated pipe with weed cloth. I left the ends open on another smaller SIP container, and the pipes filled with soil. which eventually would have filled with roots and made and an unholy mess. 

3. Don't use clear plastic totes for SIP containers. I built a couple of them thinking it would be cool to see what was going on in the soil, but the clear plastic let the water reservoir in the bottom be exposed to sunlight. And as we learned in school, sunlight on nutrient rich water allows algae to flourish. So, we wrapped those bins in the scraps of pond liner we had laying around, and the algae died. 

4. Mulch, don't cover with plastic. If you dash about the internet, a lot of the early wicking bed wizards recommend covering the bed to decrease water loss even more. I live in zone 9b, and during the last week of May it was over 100F for a week, and it's predicted to be that hot for the next week. At the end of a day, the soil is warm, and it retains that warth for hours. Adding a layer of plastic to the top will only make that worse. Mulch will breakdown over time and provide nutrients to your plants (and worms!). Just don't use a cedar or rubber mulch. The cedar (or pine needles) will inhibit seed sprouting. And rubber stinks when it's hot. 

5. We have nasty, disease infested mosquitos here in the Central Valley. Cap of the fill pipes to keep the little buggers out. 

6. Start small. Super exciting to finally have a working wicking bed. You'll want to run out and make 50 more. Don't. Make your starter box and figure out what works and what doesn't for your area.