I bet it's the soil. Is it compacted? I always add Humus and composted cow manure when planting them. My mom has some in compacted soil and they never grow. Mine are really taking off this year since I amended their special spot!

I don't think my JPF gets more than 6 inches tall - if that- since the leaves aren't real upright, but the clumps do get larger with time. It just seems to take a very long time. It's a very pretty fern, but not terribly vigorous in my garden.

Kevin

echinaceamaniac, is right. I had one for 4 years and would see other posters with beautiful large Japanese Fern but mine continued to be so small. I had amended the soil but I had very heavy clay soil. So because of the way it grew it was not enough.

I moved 3 years ago. The property had been neglected and I developed my shade garden in an area that had years of build up of leaf compost the soil was very rich. It is so rich you can pick it up with your hands I do not need a shovel. The fern has taken off. I could even divide it this year.

Sooo I would say get some compost if you do not have some home made compost and get the soil very rich. I also fertilize in the Spring.

I have found that if plants are really rootbound when planted, they are very slow to grow to size. I always tease the roots before planting...along with the other suggestions. Dig it up and take a look as well as amend the soil.

Mine have grown very well in my clay soil, but...it is on the loamy side and I am always adding organic matter and I leave leaf litter in place. Some of mine get
a fair amount of sun too. I did notice this year, that the plants are about a 1/3 to a 1/2 smaller than last year, and I can only point to the dry winter/spring. Last year they were all huge and I was thinking of dividing them and never got around to it. Probably better that I didn't since the weather has been challenging.

I did divide my large clump last fall and noticed all the divisions seem to growing much more vigorously than I expected. This really surprised me since we went into winter under an extreme drought and had almost zero snowcover the entire winter. The individual fronds however still don't reach very far into the air. In other words, it's still a short plant. It does spread outward however.

Kevin

Short plant is often caused by root bound growth. If the plant's roots were all tangled up in the pot and you planted that, the root may not have an opportunity to spread. I typically tried to tease the root and cut any loops. The area should be amended too.

You may also want to get a soil test, which may point out some nutrient defficiency.

Are the fern having root competition with anything like a maple tree or birch tree sucking up all of the nutrient and water?

Paul

probably because they hate you ...

i mean really.. when it all boils down.. what is left ...

ken

Whaaaaaat?

well.. once i rule out every other thing that i have control over.. i just come to that conclusion ..

and eventually.. i begin to hate them ... and spray them with roundup ...

why bother with a plant that hates you.. or cant thrive ... life's to short.. move on ...

lol

ken

Somewhere out there are plants plotting revenge against Ken. (I once read a book call Captain Jack Zodiac where someone is being stalked by a lawn that he attempted to kill using a unregistered weed killer causing the lawn to mutate).

Paul

Paul - lol! You must've been desperate for something to read!

Ken - PHHHHHTTT!!

Deanna