An old English stone trough was originally a shallow trough used to water animals. So when we make hypertufa troughs, we are mimicking those shallow troughs….not to mention bowls, basins, etc. But is there enough room for the roots, I was asked?
Question: “But what plants can we grow in them, and will the roots have enough room?”
Have you seen those vertical gardens? Flat as a picture frame? Most succulents and sedum are very shallow rooted plants and are perfect for these garden containers.
Any shallow rooted plant works
By nature, the succulents and sedums have a shallow root system. Since these are plants from desert-like regions, they have naturally developed a root system which takes advantage of any water available. Roots on these plants grow close to the surface and can spread out to take advantage of any moisture available in the limited area. Even the dew can work to provide the needed moisture. In most cases, these plant roots will spread out and fill the soil accessible to them, whether it be a shallow pot or a larger one. It will just adapt to the defined area in which moisture is reachable.
Remember that the soil will need to be coarse and drain well, because there is no room here for the roots to sit in wet soil. It needs to be watered thoroughly, but then drain away! During the growing period, it is important to water regularly and thoroughly.
Try any of the sedum family or cacti, but other suggestions are alyssum, thyme, oxalis or Cape Shamrock. Saxifrages are nice in hypertufa troughs, This plant has little flowers in the spring and creates a nice thick mat.
Maybe you would like an asparagus fern “Sprengeri.” This one also has tubers and will need to be brought inside for colder zones. I give mine a haircut in the spring, like ornamental grass, and have had it for years. It flowers during the summer with red berries later. ( Careful – it gets thorny.)
So plant anything you want, within reason, in your hypertufa.
That said, I don’t recommend you try a 15-20″ Daikon radish……..uh, no! Not in your little hypertufa!
Speaking of something NOT shallow rooted!
We were told in our Master Gardener classes about the giant Daikon radish which some farmers use to break up the hardpan in the soil.
Hardpan is typically in clay soil and this layer of dense soil lies just under the layer of topsoil. It is notorious for providing no drainage and restricts the growth of roots. It can even restrict air movement and organisms living in the soil. This hardpan usually reaches 6″ to 24″ under the surface and is not something you want to find in your farm field or garden. Ref: Hardpan http://www.sunset.com/garden/garden-basics/hardpan
The Old Farmer’s solution: The giant Daikon radish. The radish is sown as a forage crop but left to rot in the ground. The long root of the Daikon radish will “drill” down through the hardpan and breakup the soil for better tillage and drainage. I am not kidding. Ref: Tillage Radish http://midatlanticgardening.com/did-you-know-daikon-radishes/
The bad news: Rotting radishes smell really bad. But if you want to break up your hardpan in the soil, you may want to try it. How well do you like your neighbors?
By all means, try whatever you want in your hypertufa containers. They are open to anything with few exceptions ( Daikon probably not). If you are watering and feeding in moderation, you can grow anything.
What are you trying this year?