RE: Blueberries,
I have two rows of blueberries for a total of nine bushes. They have been planted over a period of about 3 years. They are fussy little plants in their first couple of years before they become established. I have also lost some, probably due to excessive heat. From my experience of both success and failure I can confidently suggest the following:
1) Pine needles are probably the best mulch, but they will take years to change the Ph to any significant degree. That is based on my experience with the soil here in Southern Illinois, a section of the state that was never glaciated, hilly, and has a hard clay soil--much unlike that of the entire rest of the state.
2) You will need some other type of acidifier--Aluminum sulfate will do the job quickly but interfere with fertilization (I think it inhibits the uptake of phosphorus, but I am not completely certain of that one). Elemental sulfur--bright yellow stuff--will do the job but more slowly. It will actually slowly convert into sulfuric acid (I know--scary--but this is how the process works) where it will then dissolve iron for the blueberries which need that mineral in huge amounts. As far as I know, there is no way to just simply add iron directly to the plant and avoid the Ph issue, though one old trick was to push rusty nails into the ground as a supply of iron. I have considered the same with rebar.
2) Leaves, whether they be Oak, hickory or walnut, though acidic are no where near enough to alter the Ph of the soil, at least in the clay we have here. Walnuts are particularly tricky in that walnuts play a game of chemical warfare with most other plants. the leaves and roots (and likely all parts of the tree) contain chemicals toxic to most other plants. People who have walnut trees in their backyards frequently have difficulty in getting grass to grow, and when they do, the grass often dies out quickly. If I knew I had a patch of walnut leaves, I think I would just burn them and not let them near anything that I wanted to grow.
3) When you plant your blueberries, use a nice, loose soil, preferably one high in organic matter and sand. DON'T fertilize on the first year, just let those roots become established. After the first year, check the Ph again, amend the soil as necessary and fertilize, preferably with one of the more organic types (they tend to last longer) such as the epsoma acid soil fertilizers. Don't harvest this year. In fact, pick off the flowers as they appear so as to help strengthen the root zone.
4) WATER. These plants don't tolerate drought, so find some way to keep the soil nice and moist, even in the hottest of days. I use a drip system I purchased through Dripworks. The system is perfect for this type of planting. WATER, but don't soak. Blueberries don't like to be drowned out. This is where the Pine mulch comes in. My mulch row runs about 2 feet wide and probably 6-12" high except for the spot where the blueberry plant sticks up, At those points, I level out the mulch so that the blueberry leaves rise above the mulch layer, so at these points the depth of the mulch is determined by the plant itself. I personally let the pine mulch go right up to the base of the blueberry plant, and as the blueberries get taller, the mulch height becomes less of an issue.
5) Weed barrier. I always use a weed barrier in all my plantings. Weeds are hugely competitive plants and will rob your plantings of nutrients, water and eventually sunlight if they get too tall. They also tend to harbor disease and transmit it to your blueberries, yet be immune themselves. I generally lay down a layer of newspaper (2-3 sheets will be fine as long as it does not become punctured by a weed), but you can also use cardboard (very sturdy), computer paper, or almost any paper-type produce. I have been warned about using the shiny colored type of paper that is used in magazines, but I honestly don't know why this is so important. Nevertheless as I am a teacher, I receive bundles of useless papers (from the administration, not students) each year. Instead of recycling this I reuse it (higher form of use on that triangle, but it still upsets some people). My pine needles go both below and above that paper layer. Below thinly so as to provide a nice soft layer for the paper, above to keep the paper in place. Over time, all of this will break down, but it will have done its job and if necessary, just re-apply the barrier again. It makes a nice way to discard of paper waste and help the soil all at once.
6) consider some type of cage for the blueberry plant, especially in the early years. Birds and deer will get your crop before you do unless you do something to stop this. Trust mer here. I have watched a blueberry bush produce hundreds of berries and just before they get ripe for the picking, ALL of them will be gone! I blame deer the most, but birds get in there also.
I hope this helps anyone interested in planting blueberries,
SI2305
