Are these in the ground or in pots? If in the ground and your ground is of at least moderate fertility I would give them a light to moderate amount of 10-10-10 or whatever once a year or never. I don't intend to fertilize my in ground hostas, but they grow close to annual flowers that I do fertilze so they probably get some on occasion.

Since you wish to be organic only why not just amend the area once per year with an inch or so of compost on the top of the soil.

If you were asking about hostas in pots then I don't know. haven't tried that yet.

I usually hang out on the hosta forum. A lot of us over there swear by alfalfa pellets for accelerating the growth on our hostas.

Hi Shade tolerant. How and when do you apply alfalfa pellets?

Alfalfa contains a growth hormone like cholesterol, the cell walls must be broken by way of chemical or biological mean. So early spring is a good time, as it has to be above 50 degrees for decomposition to take place. PS it stinks if not worked in to the ground.Join us at the Hosta form.