I had a quick question, because I'm trying to figure up my mulch and fertilizer needs for this Spring. I had bought my father a couple of blueberry plants, among others, because that's what he wanted for his birthday. They've been in the ground about 2 weeks and I've been watering everything, but I need to get it mulched before the hot dry weather kicks in.

In South Carolina, we have the Clemson Ag Extension which puts out great info on local plants and their care. They suggest making a mound around the plant of peat moss and sand to help with water amounts and acidifying the soil. The say that if you mound it you have to water it more often.

Being honest, I wouldn't water the 2-3 times per week they say you need to, with dry spells, using this method. I use a mulch that goes on sale every year made of 100% ponderosa pine bark. It seems to work well.

My question is, should I use the peat/sand mix on the blueberries and my azaleas and rhododendron, and if I do, will it help cool the soil and retain moisture the same way as the pine mulch? If it's going to be helpful to these plants and work about as well as the pine mulch, but I don't want to have to replace it but once a year and I don't want to water it very much more often than I do with the pine bark. I'd much rather use an acidify fertilizer to achieve the same effect with the bark. Thanks for the help.

2 Answers 2


I would use bark and not peat; in fact I do.

Once peat become dry it is seems impossible to wet again and when it is dry it easily blows away. It may be that peat and sand will do the job but I've acquired a strong prejudice against the stuff. Fir bark is inexpensive and easily available here in western Washington, so I have no cost incentive to even think about peat. I use medium size bark in my garden beds of numerous varieties of rhododendrons, azaleas, camellias, roses, and etc. Small bark does seem to 'disappear' more readily, but may be more aesthetically pleasing in your setting.

A few inches of bark mulch does a good job of preserving soil moisture, but I think you will still be watering those new blueberries two or three times per week for much of this season - such is the way with newly planted species. It just will not turn into being every day.

  • I do use the bark to good effect. I think brand I've been buying is ponderosa pine and I'd say it's medium to course. I know what you mean about it disappearing, but I suspect that has something to do with the people mowing the grass around here. Once I told my family I wasn't going to put anymore out and to quite mowing so close to it, there is miraculously some left the next year. I'm sure I'm loosing some to break down and/or squirrels as well.
    – Dalton
    Commented Mar 30, 2016 at 18:18
  • Bark itself is an excellent medium/substrate/soil for root growth - great aeration and moisture retention even after sitting (aka 'composting') for a year or more. This also affects the perceptions of 'disappearing' bark mulch..Most of the nursery plants I inspect (including those I choose to buy) from PacNW nurseries use nothing but composted fir (actually Douglas fir, which really isn't a fir) bark in their pots. I think it makes little difference what species the bark comes from - it is a by-product of the lumbering industry.
    – user13580
    Commented Mar 31, 2016 at 0:49
  • I wouldn't recommend mulching with peat moss at all. It's great mixed with soil where you need organic matter and a lower pH, but it's not an ideal mulch to put on top, especially as it doesn't last long in it's original form. Weeds probably wouldn't have trouble germinating through it. It's very, very light. It's kind of like mulching with seed starting mix. Commented Mar 14, 2017 at 6:47

Blueberries are a bog plant. They tend to have shallow roots, and they hate drying out.

You can help with this by creating an artifical perched water table.

Dig a large wide hole about a shovel deep. If using a hybrid blueberry, about 4-5 feet across.

Line the hole with heavy duty plastic.

Fill with builders sand (NOT BEACH SAND) to about 5 inches from the top, and level it.

Cut the plastic at the sand line.

Mix up a 50-50 peat/sand mix put on top of the sand. Plant your blueberry in this.

Add bark chunk mulch.

Theory of operation: As you water, it will accumulate in the sand filled plastic lined basin. Excess water will drain over the edge where you cut the plastic. The wet layer of sand will wick into the sand peat mix. The bark chips retard evaporation. This reduces your watering frequency a bunch.

Pragmatic basis: Locally our low-bush wild blueberries are found on peaty/mossy soils on top of a saturated sand layer.

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