When There Is No Soil; Gardening With Rocks and Creativity

I’ve been gardening in the hill country for about eight years. I’m in south central Texas hill country terrain — with plenty of deer, raccoons, squirrels, lots of red clay with many, many rocks of various sizes, shapes and weights, AND very little, if any, top soil. A real gardener’s dream. 🙂 Gardening here does increase one’s resourcefulness and creativity. So I hope to share some things about gardening that may be of use to you now or possibly someday in the future. I will be sharing various ways of making gardening beds in these more difficult areas, as well as tips, tricks and tidbits I’ve learned along the way. Hopefully you will find some creative and resourceful ideas that you will be able to use in your garden.

I started out my gardening experience thinking recessed beds–beds made by removing the existing soil (rocks) and replacing that with good soil that would still be at ground level– would be really attractive and would conserve water better than above-ground beds. I started with a small bed, about 4 X 6 feet, dug to a depth of about 1 foot. It took me a while to do the digging–about 4 hours per cubic foot to be exact (if I didn’t run into a huge rock that I needed help to lift out). I put the excavated rocks in piles,… and piles,… and piles. Next I took the dug-out soil, sifted it to remove remaining smaller rocks by placing a piece of 1/2 inch hardware cloth over a wheel barrow and shoveling the soil onto the hardware cloth. I then put this native, recovered soil back into the hole and added equal parts of compost and coconut coir (as well as a smaller amount of vermiculite or perlite) to fill the hole to a few inches above ground level to allow for some settling of the soil.

I also added some rock minerals to the bed. (Additionally, I usually amend the bed to meet the needs of the plants that I will be growing there before I do the planting. I try to disturb the soil as little as possible after a bed is completed so that the microbiology of the soil is not disrupted or disturbed. I put some mycorrhizal inoculant into the planting hole of each transplant to help them get well-established, and I also put some diatomaceous earth into the planting hole, especially for leafy green plants, as I’ve read the silica is taken up by the plant making the leaves less appetizing to pests.) Overall, I really DO like these beds. If you have the time, patience, and endurance to make these beds, they are a great way to garden in rocky areas, but they are time-consuming and work-intensive to construct initially. However, on the positive note, these beds are inexpensive to make and maintain. And as an added benefit you will have a lot of USEFUL rocks to use for various projects. I will cover some of the uses I have found for these rocks later in this article.

After deciding these dug-out beds were nice, but I needed a little faster way of getting beds done, as this was taking a while to do…I tried another less intensive version of this bed. For these beds, I dug the bed area out to a depth of about 6 inches and placed cinder blocks around the edges, so I could add an extra 8 inches or so of soil depth and then filled the bed with prepared soil to the top level of the cinder blocks. This worked well and was much easier. Cinder blocks are durable and long-lasting–they don’t need to be replaced every few years. They have an additional advantage of having holes that can be filled with potting soil and offer a perfect spot for surrounding your garden bed with some lovely small flowers which can attract pollinators, deter pests, and add beauty to the garden.

My first raised cinder block bed was a completely above-the-ground bed that was three layers of cinder blocks tall (about 24″) and about 4 X 12 feet in area size. The height of this bed is really nice as you can stand up to do your gardening. I really only fill this bed with about 17 or 18 inches of soil, though. It takes a LOT of soil to fill this bed all the way to the top!! I am trying to fill it a little more each year. I have really enjoyed this bed. I use the cinder block holes at the top edge of this bed to plant herbs in–which has worked very well for me. I fill the bottom layer of cinder block holes with rocks which provides good drainage for the herbs. The herbs like this, and it provides a use for some of my rocks :-). I then fill the remaining two layers of the cinder blocks with potting soil and plant the herbs in the soil-filled holes. The herbs have been very happy growing this way–as a matter of fact, maybe too happy, as they do need quite a lot of pruning at times.

In hind-sight, I would probably plant sage, thyme, oregano, marjoram, and spearmint with a two-hole (or maybe even three-hole) space between the plants (so in other words, plant an herb in one hole-skip two holes-plant the next herb) because they grow quite large. I would not plant rosemary into these holes–my rosemary has become so massive in size, that I’ve had to remove huge parts of it, and it can also shade quite a lot of the bed.

Peppermint does nicely in these holes and can be planted in side-by-side holes. I have it growing across the 4′ end section of my bed that receives quite a lot of afternoon shade, and the peppermint can cascade over the edge of the cinder block bed wall. Garlic and onion chives also do well planted in side-by-side holes. The herbs planted around the edges of the bed attract pollinators, deter pests, and serve as companion plants to some of the plants that are planted in this raised bed. The herbs are very attractive and also supply fresh kitchen seasonings and immune boosting nutrients! (Another tidbit on herbs–I also like to plant some of these herbs in pots to transport around the garden to where they may be needed as companion plants, pest-deterants, or pollinator-attractors. It’s easy to put cuttings of herbs in pots of potting soil, keep them moist, let them root, and add to your collection of herb plants for very little cost.)

The other type of bed I have used are wooden-framed beds. I have several wooden beds made from 2″ X 10″ untreated pine boards made into 4′ X 4′ beds and 4′ X 5′ beds using metal L braces to secure the corners. These frames are set on top of leveled ground. Using corner posts in these beds has been a very useful and helpful idea. I put 2″ X 4″ pieces of cedar wood about 2 1/2 feet tall in each inner corner of the bed and secure them in place with nails or screws so they stand up like posts. This helps strengthen the wooden bed frame, and serves several other useful purposes. The posts make it easy to put a piece of 2′ tall chicken wire or other wire around the bed to protect plants in the bed from critters. The posts can be used as a frame to cover the bed with netting, row cover, shade cloth, or whatever you might want to cover the bed with.

Additionally, these posts can keep a hose from running over the plants in the bed if you water the garden by pulling a hose around the garden (like I do). They are also useful for securing a trellis along the edge of the bed if needed. I have found these little posts SO useful. To fill these beds, I use a mix of equal parts of compost, vermiculite or perlite, and coconut coir. I have positioned three of these beds between the peach trees, so these beds receive mainly sunlight, but some shade–and an added benefit is that when watering these beds the fruit trees are also provided with water. I have ollas (buried clay watering pots) in the center of two of these beds, and I have planted various varieties of peppers in these beds. The peppers have been the best and most productive I’ve ever grown. The red Marconi and golden Marconi peppers have been exceptionally good! (These are sweet, somewhat elongated peppers that are definitely worth growing.) In addition to filling the ollas with water daily, I have mulched the beds with chipped tree trimmings, and I do water the beds from above as well as filling the ollas when the summer is really hot.

The first of these 2″ X 10″ (pine) wooden beds I made is about five years old and is starting to rot out at the corners and sides. So the life of these beds is limited. The other beds are newer, so they are still in good condition and have not started deteriorating. The upside of these beds is that they are attractive, quick and easy to make, and they do last for a number of years.

The final type of bed I have tried is one made of 1″ X 6″ cedar boards. This bed is situated near the fence in my garden and is a 2-foot wide bed that is about 12 feet long. It is dug out into the ground about 6 inches and then is filled to the top of the boards with soil. I have made this into a square foot garden bed. It is my newest bed, so it is too early to tell whether or not the cedar boards will last longer than the pine boards.

NOW FOR THOSE USEFUL ROCKS! Believe it or not I really do like the rocks. I used the larger rocks from the beds to make my fence around the garden. I used 5′ tall welded wire to make each cylinder into which I inserted a t-post and attached it to the side of the wire cylinder; I then filled the cylinder with the larger rocks (that wouldn’t fall out of the 2″ X 4″ welded wire openings). The rocks securely hold the t-posts in place. These cylinders are about 18″ in diameter and 5′ tall. I positioned these cylinder/posts about 10 to 12 feet apart and used the netted deer fencing to enclose my garden area. Because we are in very rocky terrain, it is not possible to dig holes into the ground for the posts without special equipment, so this provided an affordable solution for me and a way to recycle the rocks. My chicken yard fence is also made using these rock-filled cylinders.

I’ve used these rock cylinder posts for making trellises for grape vines, blackberries, cucumber vines and other climbing vegetables. I have several smaller cylinders made using 3′ tall hardware cloth and shorter 4 foot to 5 foot t-posts positioned at the ends of some of the more narrow beds. I can easily attach a trellis, or some wire or string can be strung across the bed, when needed for plants growing in these beds. Other uses for the rocks include using some of the smaller rocks to extend the edges of our driveway where some ruts were forming–they serve as a type of pave-stone that allows the water to soak into the ground without the area becoming muddy when it rains. Extra layers of rocks can be added as needed. Any left-over rocks are used for walkways, for providing drainage in the bottom of containers or pots, and as rock mulch.

So rocks really can be useful!

Here are a few final tidbits I’d like to add. Creativity, resourcefulness, variety, and diversity are very useful in gardening. There is value in using a variety of different types of containers, different types of beds, and various types of plants (edible wild plants, herbs, and heirlooms) in our gardens. It is good to have some garden plants in portable planters such as self-watering containers, clay pots, plastic pots, aerated fabric pots– so if we ever have to move, some of our garden can go with us. We will also be able to move some of our garden plants to safely in case of storms, freezing temperature, hail, or other adverse conditions. A diversity of growing methods and a diversity of plants is a good idea and helps us to be prepared for unexpected circumstances and gives us a better chance of having something in our gardens that can thrive.

In closing, I hope this article has given you some useful information and has sparked some creative and resourceful ideas for gardening. So…. Happy gardening!

Note: This article was an entry in our October – December 2014 writing contest. Click here to find out about our current writing contest.