Do you need both male and female holly to berry?

Holly Berries – What you need to know to guarantee your holly produce berries.

Berries brighten holiday decor much like holiday lights.  Bright red berries tucked in glossy, evergreen foliage or standing alone in stark contrast to a tan stem.  Nothing says holiday like holly berries.

But the abundant berries don’t just appear on their own.  Winter may be the time of year that we adore our holly, but spring is the time when all the magic happens.  We’re talking the birds and the bees.

 

 Years ago, I had a ‘Red Sprite’ Holly in my garden.  She was lonely and didn’t once produce berries.  Being that I lacked space for the much needed male holly, I would bring home from work a ‘Jim Dandy’ Holly for a week of apparent fun.  Lo and behold!  I was rewarded every winter with baby berries.
This little trick probably won’t work for anyone who isn’t in the plant industry.  But, it is a reminder that if you enjoy those little red balls on your holly, outdoors or in, you need to be prepared to plant more than one.
Here’s what you need to know when shopping for holly.
Berries on deciduous holly.

Red Berries on Winterberry (deciduous) Holly.

Do all holly require male and female plants?
 Yes.  Holly are Dioecious.  Dioecious means that they belong to a group of plants that have both male and female flowers.
While some websites claim certain hollies to be self-pollinating, this is not entirely true.  Yes, there are a few female hollies, like Foster Holly, that will produce berries without a male pollinizer.  Foster Holly, though, still have either male or female flowers making them parthenocarpic instead of the true self-pollinating monoecious.
 Parthenocarpic is based on the Greek words parthenos meaning virgin and karpos meaning fruit.
So in answer to the original quesiton – yes, most every female holly will require a male holly to produce berries.
Berries on blue holly.

Red berries cover this ‘Blue Princess’ Holly.
Image Source: Monrovia

Why did the garden center tell me my ‘Royal Family’ holly is self-pollinating?
Companies have begun planting male and female plants in the same container.  This eliminates the need to purchase a male plant and also allows for every plant to have berries.
So, while these shrubs may be touted as being self-pollinating, these hollies technically still have the male and female plants.
Two of the most common are Royal Family (Ilex x meserveae ‘Blue Prince’ & ‘Blue Princess’) and China Dynasty (Ilex x meserveae ‘China Boy’ & ‘China Girl’).
 How do I tell the difference between male and female holly plants?
If you have holly in your landscape but have never experienced the lovely berries, you likely have all female or all male.  Before you pull them out and replace with new though, you can identify male and female plants by the flowers.
All holly flowers produce four petals.  Inside those petals will be your gender indicator.
Male holly will have four stamen that supports the anthers or pollen sacks.  These contain a sticky, yellow pollen.
Yes, you can tell the difference between male and female holly flowers.

Female holly flowers have a green ‘berry’ in the center of the flower while male holly flowers have four stamens.
Image Source: walterreeves.com

Female holly, in turn, produce what appears to be a green berry in the center of the four petals.  This ‘berry’ contains the receptor for the pollen.  When pollination does not occur, the female will drop its blossoms and not produce berries.
How do I know what male holly will pollinate my female holly?
The male plant of the same species will often be the best pollinizer.  But, when in doubt, here’s a handy cheat sheet for some of the more common holly planted in the St. Louis area.
 What male holly should I use to get berries?
How many male hollies do I need to plant and how far apart?
With evergreen holly, you will generally need 1 male for every 20 female hollies.  These hollies can be up to 500 feet apart – although 300 to 400 feet is typically recommended.
Winterberry (deciduous) holly need to be closer than evergreen holly.  You’ll want to plant 1 male for every 5 to 10 female.  Plant the male holly within 50 feet of the female holly.
 
So whether you’re decorating for the holiday or adding winter interest to your garden, holly, with its cheerful red berries, add ornamentation to any area of your home.

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