Last Spring I removed nearly all the turf from my small property in Fairmount and am in the process of landscaping with plants that are either native to North Texas or suitable for our climate. It has been a wonderful experience and the perfect project to keep me occupied during a pandemic, but not without drama.
First of all, anyone learning about plants native to North Texas, such as hollies, usually hears them described as being drought tolerant and requiring little irrigation once established. Those two little italicized words must be emphasized. What I’m finding out is that the sun and the heat in this climate require a lot more water than I originally expected, and I’m still calibrating and experimenting with my drip irrigation system. My ongoing Holly Experiment started with me planting a bunch of Nellie R. Stevens, Dwarf Burford, and other hollies starting in the Fall of 2019. The Nellies and the Dwarf Burfords were planted in a row to form a hedge, and, shortly after planting, I put down drip irrigation that I ran for about 45-60 minutes every time it didn’t rain for about a week, and I hand watered with a couple gallons of my personally fertilized water about once a week. All my hollies looked healthy until it started getting really hot in late June/early July. I very quickly noticed the Nellies’ leaves started to look like they were dying. The leaves started getting large brown spots.
At first I thought they must have been infected with some kind of virus or disease – I didn’t even suspect I was under watering. In fact web sites describing these hollies often warn against over-watering, saying leaving these plants with “wet feet” can lead to root rot from which they cannot recover.
Then I remembered a seminar on home landscaping I attended late last winter hosted by the Tarrant Regional Water District. Everyone at the event was given a free moisture meter:
Yes, little Froggy looks like a cute toy for kids; I never thought I’d actually use it. I nearly forgot all about it, until my hollies started dying. Not-so-cute ones can be purchased on Amazon for less than $15, and they have higher-end digital ones. I did a couple quick sanity tests to make sure it generally works. I’m not sure how accurate it is, but when I jammed Froggy into the ground next to one of my Nellie R. Stevens the meter read totally dry! I had no idea about the degree to which I was harming my poor plants by under-watering.
In a panic, I immediately amped up the volume of water all my plants get. I started running my system two hours per zone, 6 days a week. Keep in mind I recently removed nearly all my turf, replacing it with plants, so I have many unestablished plants. I’m hoping to greatly reduce my watering over time as they become more established. Follow-up articles are guaranteed.
My hedge of dwarf burfords in the front yard still looked healthy, so I focused on the Nellie R. Stevens in the back that were burning up in the sun. Months earlier I visited Ewing Irrigation supplies on Hulen Ave. to buy 1/2″ dripline. I didn’t give a lot of thought to the emitter flow rate – .6 gallon per hour (gph) seemed to be the most common one so I got that. I should have got the .9 gph, but even that would have been too little. Luckily I had a bunch of 2 gph drip emitters.
I applied two of these to each Nellie R. Stevens holly, jabbing the barbed end of the dripper into the 1/2″ dripline and adding a few inches of 1/4″ tubing to the other end and situating the tubing near the base of the plant.
The 1/4″ black tubing can be moved around, further away from the base of the tree as the Nellie becomes more established. By the way, when reading up on drip irrigation you’ll often read to irrigate at the plant’s dripline, or just beyond. I’m sure that’s true, but when you put plants in the ground initially all the roots are likely to be well within the dripline, so if you water at the dripline the roots won’t get any water. But I’ll gradually move both the 1/4″ and 1/2″ tubing further away from the base of the hedge as it grows. It’s not a perfect process and the main variables of sun, temperature, soil, and rainfall change over time, creating potential for a lot of paranoia and second guessing ourselves. But as soon as I added these drippers and increased the watering time to two hours, six days a week, things started to turn around. Even in the leaf-damaged picture above you can see a lot of green shoots coming out, like these plants were just dying to burst out with new growth as soon as they got some water.
A month or so later there is a lot of new growth. Yet the tender new growth still burns when we get scorching sun and near 100-degree heat. It seems that the soil around my Nellie hedge seems to be exceptionally well-draining. Even though I give it quite a bit of water in the morning and the meter reads “wet”, sometimes the reading will already be dry by the end of the day. And there aren’t any other plants around that would be stealing the water. I’m thinking that young Nellie R. Stevens hollies simply drink a lot of water during their growing season.
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