Alkaline soil

[Warlock]

So i am going to enter in the Native Tree 5 yr Contest.

What do you do if your tree loves Limestone like my Texas Mountain Laurel. Also my Cedar Elms also thrive in the same.

Would they not be better off in limestone material? i can get bags of limestone screenings (3/8" minus) very cheap. The material drains very well.

There is not much here in BN on alkaline soils.

 

[63pmp]

You can just apply a small amount of Ag lime to your potting mix when creating it. Sprinkle teaspoon over soil every now and then. Depending on how much water they get, might be once a month. Monitoring soil pH will give you an idea of how it's going. With Ag lime it should reach a max of about 8.4

 

[Warlock]

You can just apply a small amount of Ag lime to your potting mix when creating it. Sprinkle teaspoon over soil every now and then. Depending on how much water they get, might be once a month. Monitoring soil pH will give you an idea of how it's going. With Ag lime it should reach a max of about 8.4

I may have used wrong title. I am looking at native trees specifically in central Texas that grow in limestone. We have alot of it around here.

 

[0soyoung]

I may have used wrong title. I am looking at native trees specifically in central Texas that grow in limestone. We have alot of it around here.

My recollection is that things grow in a thin layer of soil ATOP Austin's limestone, not in it. That layer of soil is somewhat acidic, else the area wouldn't be covered with live oaks like it is.

 

[Warlock]

Live Oaks are different.. That's why I only mentioned TML and Cedar Elms...

 

[Warlock]

My recollection is that things grow in a thin layer of soil ATOP Austin's limestone, not in it. That layer of soil is somewhat acidic, else the area wouldn't be covered with live oaks like it is.

I have my Live Oaks in something more acidic and organic.

 

[Michael P]

What is the pH of the water you use? Most tap water in the western 2/3 of Texas is alkaline, and will raise the pH of the soil naturally over time. In other words, I don't think you need to do anything, just use your normal soil mix. I don't do anything special for my cedar elm.

Plants that are adapted to high pH soils do not necessarily like or require high pH. They tolerate it, which means that they can out-complete any species that require acidic conditions in their environment.

Osoyoung, the native live oaks in Austin are hybrids of Quercus virginiana and Q. fusiformis. They inherit high pH tolerance from the fusiformis parent. And virginiana grows well in moderately alkaline soils. (Simpson, 1988.)

 

[Dav4]

Yeah, I was going to say there are many Cedar elm bonsai here in GA that absolutely thrive in typical bonsai soil mixes without any specific tweaking to the mix or the ferts.

 

[Leo in N E Illinois]

Dermatophyllum secundiflorum used to be known as Sophora secundiflora, these are the botanical names I found for "Texas Mountain Laurel", which botanically is a legume, not at all related to Laurel, which is most commonly used name for various Rhododendron and Kalmia species. Another common name is mescal bean.

I've seen mescal bean planted "everywhere" when I was in the San Antonio area. From how well they were doing, and their wide planting, I would assume they are really not fussy about soil pH. You probably have to do nothing to keep them happy, as your tap water will have enough lime in it to cover their need for calcium. But it won't hurt to top dress your potting media with the limestone chips you have access to.

If foliage picks up a yellow tinge, alkaline soils tend to block uptake of nitrates. Use a fertilizer with ammonium as the nitrate source, or use organic amino acid type fertilizer. This will get around the pH induced restriction on nitrate uptake.

Generally top dressing a potting mix with some limestone, or horticultural lime, or even crushed oyster shells will work. I find once a year is sufficient for my few lime loving orchids. Crushed oyster shells are sold in feed stores as a calcium supplement for chickens. Cheap.

But I don't think Dermatophyllum is very fussy about pH, you really might not have to do anything to adjust the pH of your soil.

 

[ShadyStump]

I've run into the same question researching pinion pines. What I noticed from just gardening and indoor starts is that simply failing to flush the soil when you water will eventually allow some alkalinity to build up across the surface, so probably throughout, the soil. But generally, like others have said, most trees can handle a range of pH levels. A bit of that limestone mixed in your soil wouldn't hurt if you're worried about it, though.