Here are some 1st year tree peonies which are just starting to come out this year. They usually make no more than 1-3 leaves on the 1st year while there has been a case where I've gotten 6 leaves before. These have just started coming out after a good week of rain and temperatures slightly above freezing.
The 2nd year tree peonies are usually much larger, and on average are further along as they typically get up to around 6 inches tall with more like 4-10 leaves depending on the species and vigor of the seedling. Some of them will even gain a little bit of height forming a small stem. The potted ones are usually much further along.
A 3rd year tree peony from seed will typically have multiple buds as opposed to the typical 1-2 from a 2nd year, and have a much thicker, established woody stem as shown below. This happens to be the only one I kept from the generation born in 2011.
Here are some of the grafted Japanese tree peonies that were planted last summer as 1 year old grafts. These are more or less on par or slightly ahead of my 3rd year tree peony grown from seed as some of them have grown their own tree peony roots, no longer relying on the herbaceous nurser root. I grew some of them almost sideways as an attempt to get more shoots and more root development.
Moving on, here are some of my itoh peonies that were purchased last summer or spring.
Bartzella: This one is making up to 15 buds which is pretty impressive from having only 2 original stems.
Cora louise: This one has most of them right around the main stem.
Early Arrival: 9 shoots are not bad for starting from a very small plant. These all should be up to flowering size.
Lemon Dream: This one won't flower, but it's well ahead in development due to the nursery pot.
Keiko: This was divided up from a large 4 gallon monrovia pot so I have a couple dozen divisions which are just starting to show themselves in the last few days. I hope the eyeless divisions will sprout too as I can always use more peonies.
Old Rose Dandy: This one appears to be really spreading out quite a bit for an itoh peony.
Here are some of the herbaceous seedlings which are the glossiest out of the 3 categories, and these won't form woody stems at all. They also produce nector which attracts a lot of ants. Unlike tree peonies and itoh peonies, these also have very round leaves, and appear to be more prone to certain fungal diseases such as mildew than the rest. The good part about them is that they can be used to graft tree peonies.
Here are a couple of seedlings.
These clumps are over 15 years old, but they don't really increase in size once they get to around 20-30 stems per clump as they don't have a way of sending rhizomes or new growth further away. They do sometimes drop some seedlings. There's a seedling in the 3rd picture.
Here are a bunch of them that were transplanted to this spot back in the fall of 2011 and they have already almost reached their full potential as herbaceous peonies only take about 5 years to max out their growth potential as opposed to tree peonies that can take many decades to reach their full size.
I have a few garlic plants growing between them.