Twelve Questions Tree Farmers Ask Before Their First Bulk Gel Order

The enquiry usually starts the same way: a grower with 40,000 seedlings ordered for November and a quote for 600 kg of gel on the desk, wanting to know whether any of it is necessary. The questions that follow are remarkably consistent across calls from Georgia, Victoria and Andalusia, which suggests they are the right questions. Here are the twelve, answered with the numbers we would give a grower on the phone rather than the ones that make the product look best.

They are grouped by what they are really about: dose and cost, soil and water, and supply and storage. If you only read one section before ordering, read the second, because that is where most first orders go wrong.

Questions About Dose and Cost

How much do I actually need per tree? For a 45 litre root ball in a 600 mm pit, 40 to 60 g of dry polymer mixed through the backfill. For bare-root stock in a 300 mm slit, 20 to 30 g. Multiply by tree count, add 10 percent for spillage and re-dosing, and that is your order. A 25 kg bag covers roughly 450 to 600 trees at the tree rate.

What does it cost per tree? At 4.60 dollars per kg, 50 g is 23 cents. Add 6 to 10 cents for the labour of mixing, and call it 30 cents per tree. Against a 3 dollar seedling and a 1.50 dollar planting cost, that is under 7 percent of the establishment cost for the first two seasons of water buffering.

Will it pay for itself? Only if it prevents losses or saves irrigations. At 5 percent survival improvement on 40,000 trees, you save 2,000 replants at 4 dollars each, which is 8,000 dollars against a gel cost of 2,760. If your survival is already 95 percent, the gain is small and the money may be better spent on mulch.

Can I use less and still see a benefit? Below about 25 g per tree the effect in a sandy soil is hard to measure. Half-dosing a large program is the most common false economy in the category, because the result is indistinguishable from no treatment and gets blamed on the product.

Questions About Soil and Water

Does it work in clay? It works differently. In clay the soil already holds water, so the polymer’s job is to improve infiltration at the surface rather than store water. Cut the rate to 2 to 3 kg per hectare and place it in the top 50 mm with compost, or skip it.

Does it work in pure sand? Yes, this is where the effect is largest, but placement matters more than dose. Put the gel 100 to 150 mm below the surface, not in the top 50 mm, because the surface layer dries out and the beads desiccate.

What about my bore water? Above 1.5 dS/m or 300 mg/L calcium carbonate, expect the effective absorption to fall by half or more. Test 5 g of gel in a litre of your own water before you buy a tonne, and adjust the dose upward if the granules stay small.

Do I still have to water? Yes, at least three times in the first month for bare-root stock. Gel extends the interval, it does not remove the requirement. Programs that plant into dry soil and rely on polymer alone lose trees in the first dry spell, and the polymer gets the blame.

Will it affect my fertiliser? It can, slightly. The polymer holds cations loosely and can reduce the immediate availability of potassium and ammonium close to the granule. Keep the gel 50 mm away from a concentrated fertiliser band, and do not mix urea directly with dry granules.

Questions About Supply and Storage

How long does it keep? Two years in an unopened, lined bag in a dry store. Six to nine months once opened, depending on humidity. On the Gulf Coast, halve those figures and keep the bag clipped and off the floor.

What grade should I order? A potassium polyacrylate, 1 to 2 mm cut for mechanical planting, 0.5 to 1 mm for nursery media, with absorption under load quoted at 20 kPa rather than free swell alone. If a supplier cannot quote AUL, ask what they can quote and treat the answer as a measure of how seriously they take agricultural sales.

Can I get it in time for planting? Lead time from a stocked supplier is one to two weeks; from a manufacturer running a specific screen cut, four to six weeks. Order before the planting window, not during it, because a late delivery in week two of a six-week season is the same as no delivery. The lead times and cuts available for agricultural grades are set out in the SAP powder product pages.