I'm no scientist, but I use them around my roses and azaleas. It takes quite a while for the needles to break down. That would suggest, at least to me that they would not release a lot of acid quickly. I think they are quite lovely!

I'm curious, if you have high alkaline soil, how did you have a pine tree? Was it old?

Hi, I live in Bastrop and in the Lost Pines. Pine needles over time do make the soil very acid. It is good for those that like acid soil of course. It does take lots of pine needles over time to do this however. If you add other organic matter to counteract this it will not harm your non acid loving plants though. It is good looking and good for the environment. I have loads if you want more! Lynn

I'd always heard that pine needles/trees were allelopathic. I use it as mulch in pathways, but not around other plants. I was always afraid it would kill my plants.

Hi folks,

It takes tons of pine needles to move the soil pH very much so no worry with using them as mulch. I like to rake them into rows, cover the rows with fallen leaves, and then mow over them and catch them in a bag. My neighbors think I'm nuts but I use this chopped mix as mulch all over the beds and gardens. I think it looks better than almost any other mulch and is really long lasting. The shredded leaves breakdown thru the year and slowly contribute leaf compost.

Cynthia, it is weird to associate pine trees with alkaline soil but there's many that do well. I think most of the ones around my area, south, and into the Bastrop/Austin area are Austrian black pine, Loblolly, Ponderosa pine, and the good ole Slash pines. There's a really good one that looks like a big Xmas tree and loves alkaline soil. It's called Eldarica pine but alas, there's none in my yard.

I had wonderful Eldarica pines (Afghan pines) around our place out west (Big Spring, TX). They did quite well in that alkaline, dry climate. Here, north of Ft. Worth, I have two young Japanese Black Pine doing quite well. I understand the Austrian pines would tolerate this tight clay, alkaline soil also. Nice to know I can utilize the needles when available. I was wondering about the "allelopathic" thing, though.
J.D.

Bill, thank you for the information. I guess I need to look at the local pines differently. Mowing them up makes sense. I use mine around roses and azaleas.

If they suppress something it's not those plants and they allow me to mulch without burying the roots. I wish they would suppress the English Ivy that runs wild through the azaleas along with honey suckle. The spring and summer bulbs don't seem to mine either. Maybe I just don't have enough. When It's thick it seems to help keep down the weeds.

I saw pine needle mulch at the Tyler rose garden. I've used it

If you google 'allelopathic pine needles' or just 'allelopathic pine', you'll get lots to read about. They've even done studies to see if the 'killing' effect of pine can help in natural weed control in certain areas. From what I've seen and the little I've read, it seems to have the greatest effect on turf grass and grass type plants rather than regular plants.

I've never noticed any harm but the effect on grasses would make me think to keep it away from corn in the veg. garden or things like fountain or aztec grass in the landscape. I've not had any issues using my leaf/pine needle mulch but.....

The other thing I like about them is that they are slow to break down because of the lignin and other compounds in their cell walls. Where I garden it is mainly black caliche type soil that needs help to unlock all the good stuff in this clay type soil. I really mow the heck out them two or three times to get them shredded up, then mix with leaves and grass clippings and then till or dig all that into new garden areas.

The shredded leaves and grass clipping breakdown quick adding humus but the pine needle pieces stay for a very long time helping to keep the soil loose. I've done this many times and never had any bad effect on the plantings, whether veg. or landscape.

I'm going to Colorado to visit my MIL soon. She has a pine tree in her yard and hates the needles. I know she wouldn't mind if I stuffed as many bags as possible in my car!
So, I'm wondering, would Colorado pine needles be any different to use as mulch than local needles?

This year I used pine needles ordered and shipped from Georgia. Since I live in West Texas, there are few pine trees to get needles from, and those places that sell them are too far away. I also wanted to use them as mulch, because my dogs eat other mulches! Using pine needle mulch has worked out great for me so far. I put down newspapers, then compost, then pine needles on top. I have had no weeds, and great moisture retention. All of my plants have thrived, so I am very pleased with it. My dogs will walk on the mulch, but have never eaten it or put it in their mouths. I have a friend who says her dog refuses to walk in her pine needles because it hurts her paws! Anyway, I highly recommend it over other mulches and it hasn't yet had any effect on our alkaline soils. When it starts getting packed down, all I have to do is fluff it a little with a rake, and it looks fresh again.

Colorado needles would work fine. You might even be able to sell some as 'Fancy Imported Pine Needle Mulch' ;-)

I have used pine needles as mulch for years and I find it to be very effective in blocking weeds and retaining moisture. In many areas of the garden (except places where I use self-seeding annuals), I lay a layer of newspaper down beneath the pine needles. Talk about week control!

Being a native from Georgia I will share this. Pine needles are most likely the #1 ground cover there. All home builders use it in their landscape. Its used anywhere and everywhere in the landscape. At any Home Depot, Lowes, or Walmart there is a tractor trailer full of bales. Price ranges from $3-3.75 a bale. It does provide good moisture retention and decent weed control. A lot times the straw would have weed seeds in it and you would have some suprises pop up... It does not retain its color very well and needs replinishing as each season rolls around. I always used it in several areas of my yard. However, DH hated it, but after having a home that required 150 bales a year I could see his point ;0) I kinda miss seeing it here in Texas. We did not have a lot of cedar mulch there so I do like having that here.

Wow! So much advice... Thanks. Actually, I was going to take the lazy route and just pile the needles on top of wintering plants in a mound as a buffer against the cold. I used to live in New England I used to do this with a lot of success with some of my more tender plants, or when we had a winter without a lot of snow (which is very insulating). I don't know what kind of pine tree mine is (was) -- it is very long needled and probably 20-25ft tall -- definitely something that a previous owner planted rather than a native since I am in town and I suspect that most of the trees were planted back in the early 60's when the house was built. There's an elm, a redbud, a pecan, what I think is some kind of mesquite, a crape myrtle, and a juniper. Of all these the redbud is the healthiest --the pecan loses branches fairly often from those borer things that make branches fall off looking like they've been gnawed by teeny tiny beavers, the very tall crape myrtle gets the "drips" in the summer and is way too tall to spray it myself (this year I am going to cough up the money to have it pruned way back, although I like the natural look much better). My juniper is very tall but of course the lower and inner branches have a LOT of ball moss. Sigh. And the pecan took a hit this year from laden-down pecan-filled branches from all that rain we had. I am so fortunate to have all these trees in a pretty small yard and I really think I need to invest some money in getting them pruned by an arborist (but it's soooooo expensive for someone who really knows what they're doing). It's so hard to keep up with all this when working full time and having so many other "creatures" that need care, but I guess all of you know about that!

I have used pine needles as mulch in all of our beds for years with no problems. I only have to add to them every 3 years, because they last SO LONG. I can't tell you how much I love them. The needles sort of weave together and form a mat, so they don't wash all over the place when it rains. Weeds absolutely cannot get through them. In fact, I put a thick layer of pine needles down directly over grass in a few areas of our yard, and they took care of the grass almost immediately. I was able to pull the pine needles back and plant the following spring, and I didn't burn all those calories digging out sod :-)