We have a few acres here in north Spain which we just started to work on. We are about to plant some trees, only problem is, it's pouring down since days and the soil is quite soggy. This is mild oceanic, very humid climate (1500mm/year) and the soil is very sandy and acidic. So we thought we have good drainage. Still the planting holes we dug gave us some surprises : one day after digging them they filled with water. They are over a foot deep so they must have filled from surrounding ground water and surface seepage not direct rainfall. Only a few holes that were at the edge of the terrace remained empty, the rest are full to the brim - 8 paces distance made all the difference between holes and how they behaved. I did observe a good 2 inch decrease of water within a few hours when it doesn't rain intensively, but with heavy rain they keep refilling. Also digging down a foot next to the water filled holes, the soil looks normal, not like a soaked sponge anyway, so it doesn't look water logged. Still the newly created holes fill up quite quickly especially with this non stop rain.
This raises some questions:
1 We just bought our 2 year old bare root fruit trees - should we go ahead with planting despite the drencehd soil? At least we don't have to water... Just need to remove water form the planting holes and backfill with the currently rather soggy soil.
2 Would the hole flooding effect occur if there is material in the holes? My gut feeling is that water is drawn in by the lack of resistance I.e. Lack of material and the soil is otherwise well drained (hence the quick reaction tom rain and pause in rain) Or are the flooded holes an indication of a (seasonaly) waterlogged soil? If so:
3 would throwing some turf in the bottom of the holes and then backfilling with native soil to create a slight (few inch) mound above grade be a prudent move in this case?
I have planted into conditions like this and haven't noticed any problems. Especially in dormant times, the trees should be able to handle some soggy cycles in the soil. I wouldn't try to overthink the backfill - just use the same soil as the surrounding. Once the soil is filled up, they should be doing ok.
All the native trees nearby are experiencing the 'soggy' soil and they have been surviving it without any big problems. In the past 4weeks, I have gotten 100in of snow (2500mm). And my plants will be ok, they are used to nature.
Iterations are fine, we don't have to be perfect
Location: Cantabria, Spain
posted 5 years ago
Thanks for the reassurement! We will proceed with planting... and bring buckets to empty the water filled holes