Soil Polymer Crystals as Mulch for Container Gardening
I am experimenting with using soil polymer crystals as mulch for containers this week. You’ve probably seen it at the local nursery once it’s fully water logged, but didn’t know what it was. It looks like clear jello crystals in the soil. This stuff can retain an incredible amount of water and can be helpful for container vegetable gardening because it it so light weight. Soil polymer crystals are natural and will eventually break down and compost in your soil.
Adding soil polymer crystals as mulch to your container vegetable garden brings the admirable qualities of water retention and weed blockage to your finger tips. Natural mulches can be anything weed free – grass clippings, hay, coconut fiber, sphagnum moss. Even shredded newspaper or office paper will do the trick.
A soil polymer will also help your patio and indoor plants retain water. Its an additive that absorbs 400 times it’s weight in water. Several brands are available. You can get these Water Beads at Amazon or try your local garden center. They come in different sizes and start out looking like large grains of sand.
Inflate your Soil Polymer Crystals
Soil Polymer Crystals – for my experiment I used
- 1/4 teaspoon of crystals.
- 1 1/2 cups of water. You could also use weak compost tea for added fertilizer benefit.
- A container of sufficient size to “grow” your crystals.
- The crystals became 1 1/2 cups of expanded, jelly like, material. I’ve put 1 drop of green food coloring in it so it shows up better in the pictures.
- It only took about 30 minutes to absorb the water and expand fully.
I could have added these crystals to the soil when planting. There are several benefits of adding directly to the soil, including fertilizer placement at the roots of your new plants and that there is no added weight to the container. How much should you add? Well, figuring that 1/4 a teaspoon of crystals will expand to 1 1/2 cups, I think 10 cups of soil to 1/4 teaspoon polymer mulch works well. You don’t want your plant growing in soil polymer crystals instead of soil do you? (I wonder if that would work? Next experiment!)
I have inflated my crystals and placed my polymer on top of two plants that are notoriously under watered at my house. I’m using this as a mulch on top of the soil because I want to see how long it takes the soil underneath to absorb the moisture from the expanded crystals. And I want to see what becomes of the crystals. After 1 week the crystals have become tiny again and are sitting on top of the plants. I gave them water and voila! More mulch to slowly water my plants.
If you are going away for a week or so, spread the expanded soil polymer crystals over the soil in each pot, to a depth of 1 inch. The polymer slowly releases water and when you return your plants will be in great shape. You must water your plants first though. It helps begin the wicking action needed to maintain moisture.
Your batch of soil polymer crystals will dry out naturally and be ready to use again.
Make a big batch: Put a couple of tablespoons of the product in a 3-gallon bucket and fill the bucket with water. In about 15-30 minutes, the polymer will have absorbed most of the water and swollen to fill the bucket.
Caution! A couple of tablespoons of these crystals in a bucket looks mighty small, and you’ll be tempted to add more – Don’t! Take it from me, you’ll have it all over your floor and it’s very hard to pick up.