Do different species of holly cross-pollinate?

I have two Japanese Hollies (Ilex crenata "Helleri") and I looked online and the kinds they sell ("Helleri" and "Sky Pencil") and that I bought ("Helleri") are all-female, and there are no male kinds to buy. I also have one small Blue Prince holly and one Blue Princess holly. I know the Blue Prince will pollinate the Blue Princess because they are Ilex x meserveae, but will it pollinate the Japanese hollies? I think they would look good with their small leaves and some berries on them.

Probably not. It depends, perhaps, on what the "x" might have been.

And if they did cross, you would have no idea what the result might look like.

I'm speaking from a mighty poor knowledge of horticultural genetics; Ma Nature's I know fairly well, but we fiddle things around too much.

It is most unlikely that the 'Blue Prince' will pollinate I. crenata. However, it is possible that some specimens of Ilex crenata are self-pollinating. Some of the larger nurseries sell male clones of this species, but you might wait & see if yours produce any berries on their own.
Iris

You're aware that the berries on crenatas are black and inconspicuous, right?

R

Well, I figure that any berries would look more interesting than no berries. Red berries would look better but black would be okay. And maybe I could try planting the seeds and end up with plants with red berries and small leaves? Or even bigger black berries and small leaves? Or medium leaves and beige berries by that matter. Anything would be interesting to me.

I assure you if your Ilex crenata produces fertile berries, which it won't unless you find a male plant, the offspring will look exactly like the parents.
Iris

Well, I don't care if the seeds are fertile, I just want berries on my Japanese Holly plants (Ilex crenata "Hellerii"), which are FEMALE plants.

I have _no_male_Japanese_Holly_plant and cannot buy a male Japanese Holly plant because _no_nursery_where_I_live_sells_male_Japanese_Holly_plants. That is why I am asking if a _different_species_of_holly will fertilize the flowers on my FEMALE Japanese Holly plants, so my FEMALE Japanese Holly plants will form berries whether or not the seeds are fertile. My FEMALE Japanese Holly plants won't form berries unless the flowers are fertilized by something and _there_are_no_male_Japanese_Holly_plants_available.

What OTHER SPECIES of holly will fertilize the flowers of a FEMALE Ilex crenata?

I think you missed a couple of points. First of all, there are a few nurseries that sell male I. crenata by mail order. Look online. Someone pointed out that female I. crenata occasionally produces berries without being pollinated. They are probably sterile. And most important, there probably isn't any other species that will pollinate I. crenata.
If you want a similar species that easily produces nice red berries for the winter & can be used for bonsai, try winterberry, I. verticillata. There are many nice improved female cultivars, and male pollenizers are widely available. Of course it is deciduous, but that only shows off the berries.
Iris

jonkatzmail wrote: What OTHER SPECIES of holly will fertilize the flowers of a FEMALE Ilex crenata?

I put your question to a nurseryman friend of mine. According to Fred Galle's book "Hollies", the only x crenata we saw was a glabra x crenata. Ilex glabra is an American native that also produces black berries. It grows in the same places as vomitoria, cassine and opaca, all of which produce red berries - and sometimes yellow. Apparently there are no know crosses. To boil it down for you it doesn't look like the blacks and reds cross, or produce fertile offspring if they do.

Looking over the crenata list, the 'compacta' varieties of I. crenata are male. Ilex 'compacta', or I. crenata var. 'compacta' should be easy to find. It's a common landscape plant. Since "Japanese hollies" aren't sold for berries but more as a cheap alternative to boxwoods, asking a retail nursery for "male" vs "female" is probably pointless because they don't know/don't care - it simply doesn't matter.

Just as an aside, you may get a better berry set on your helleri by not watering from overhead while it's blooming, and keep it out of the rain too.

I hope this helps you find some peace.

Well, that helps some, I would have to find something labelled "compacta" to have a male plant of Ilex crenata.
I wonder about overhead watering or being in the rain when "Helleri" is blooming, but I guess without having a "compacta" I can worry about that later if I ever find a male.
I was hoping something else would pollenate it just so it would be easier to get berries, but its more important to have good looking bonsai first before worrying about berries anyway....

You've probably walked right past 'compacta' and didn't even know it. Google it and look at the pictures...
http://www.southerngrowers.com/compacta_holly.html

Since it's grown as a cheap replacement for boxwoods, it's probably the most common '"Japanese Holly" out there. I bet I could go to Lowes and Home Depot and find plenty right now. You'll often find it sheared into cone topiaries too.

As I suspected, guess what I just saw at Lowe's...

Right next to the 'helleri', 'soft touch' and 'sky pencil' was 'compacta' in 1 and 3 gallon pots.

Russell Coker wrote:As I suspected, guess what I just saw at Lowe's...

Right next to the 'helleri', 'soft touch' and 'sky pencil' was 'compacta' in 1 and 3 gallon pots.

I went to two different Lowes today and guess what I saw?
One Lowes had NO Japanese Holly of any kind. The other had only "Sky Pencil" in one size pot.
You have to realize I live in "The Upside Down And Backwards State" = Indiana
Maaaaaybe in a hundred years we will have newfangled things like both sexes of Japanese Holly ["It would be a scandal to have them foreigner bushes mating all the time! We need to protect the kids!"] and if we are lucky we will get the new TRS80 Color Computers with 4k RAM and cassette tape backup!
http://en.wikipedia.org/wiki/TRS-80
http://www.radioshackcatalogs.com/videos/1980_trs80_color_computer/
I can't wait!

Indiana? Please. You're talking to someone who lives in Alabamastan.

Russell Coker wrote:Indiana? Please. You're talking to someone who lives in Alabamastan.

Oooohhhh Nnnnnooooo!!!
If they find out someone from there can read they will know you must be from somewhere else and drive you out! Oh wait, you can tell them you can't read, you can only write. Then you are safe....
I wonder if you can use your pet opossum to drive them off if they don't believe you? I saw someone from there online who has a pet opossum, so everyone must have one, right?

I even tried Home Depot, and their selection of plants is even worse. And K-Mart, and that was a waste of time, although they did have a few teeny, tiny Junipers for $4 that may or may not make mallsai-wannabes.
I am hoping that maybe when the weather cools down a little then they will get some more things to sell at Lowes....

jonkatzmail wrote: I wonder if you can use your pet opossum to drive them off if they don't believe you? I saw someone from there online who has a pet opossum, so everyone must have one, right?

Times are tough, we had to eat him.

Tried possum once...tastes like chicken.