I've found that either I'm no good at re-potting avocados, or avocados are no good at being re-potted. My avocado has always sulked after root-disturbance, even when I think I'm doing things right; and I've seen others kill avocados when re-potting to and from a variety of potting mixes.

My current mix isn't really the Gritty Mix...it's mostly screened fir bark, uncomposted, with screened Turface and red Scoria (lava rock) - a sort of modification of what JustaGuy (past forum member) had used. In my case, it wasn't the mix to blame, as experimental as it was. I speculate that I simply wasn't maintaining consistent moisture in the upper inches of mix, which led to leaf-loss, lateral root-loss, and slow recovery after re-potting.

This Summer, I've made a concerted effort to really saturate the avocado mix every two days in 90F+ heat. As a result, the plant's vitality has greatly increased....of course, I've also been fertilizing weekly. The avocado is overdue for a re-potting....but it's too late this season.

Josh

Alexander,

I start several hundred pawpaws each year, and have experimented with several mixes. I don't have experience with the magnolids you mention. I have grown other plants in Gritty mix--not pawpaws. In my experience, pawpaws need plenty of moisture, and I believe Gritty mix may be just too fast draining for pawpaws. You might have to use a watering regimen almost like a hydroponic setup to make it work. Pawpaws are also very slow starting plants. They are going to be in containers longer than other plants, before planting out to the ground. Any problems created in mixes, watering or fertilizing are going to be magnified.

I have had good success using 5:1:1 for pawpaws. It's slower to drain than Gritty, and because of the high content of pine bark and peat, the pH starts out low, which is important for pawpaws. You should keep the pH under 5.6 for pawpaws--think blueberries. I have not measured the pH of Gritty, but perhaps it is on the high side. Have you tested the pH and alkalinity of your water?

Pawpaws also seem to be set back more than other plants during potting up.

Another thing I learned recently--in a very costly way--is to avoid sand in the mix. The sand I used had a high limestone content--high pH--and those pawpaws suffered badly.

Good luck,
Marc