Rose Hips, and Growing Roses from Seed

Rose hips have been ripe and full-colored for some time now. In the case of the species, hips represent roses' primary ecological contribution (food for wildlife), and in many other roses hips are an important part of the late-season display.

Ripe hip on R. carolina, on the Natchez Trace

Although they are seedy and not very fleshy, hips are edible; in World War II in Britain, the hips were gathered for use as a vitamin C supplement. There are also many recipes for rose hip jam. Some amateur breeders have expressed interesting in selecting for hips for human consumption, but as far as I know little has come of this effort-- so for edible fruits from Rosaceae we'll have to stick to such staples as cherry, apple, pear, strawberry, peach, plum, et. al.

Hip on R. spinosissima repens at the National Arboretum

As many roses hail from regions of the Northern Hemisphere with appreciable winter cold, the most common method for breaking the seed dormancy is stratification. Seeds can be left in the fridge for months, up to a year or two. Many will not germinate even when given this winter period, so pots of rose seeds should be kept for several years after sowing. The wearing off of natural germination inhibitors is also a factor.

Unripe hip on large flowered climber 'Stormy Weather,' at the National Cathedral Bishop's Garden

Conventional wisdom dictates that seed be collected when the hips are ripe, but in practice it is possible to have equally good germination rates if the seed is collected slightly early. Once I was able to raise seedlings of Rosa rubiginosa from hips that were completely green-- so if you are in a pinch, late-season hips that aren't visibly ripe can still yield seedlings.

Here is the method that has worked best for me:

1. Clean the seeds and wrap in a damp paper towels, wet with dilute Captan (fungicidal) solution; store in labeled ziploc bags
2. Refrigerate for six months before checking the bags for any germinations; remove and pot seedlings as they appear
3. Water the potted seedlings with dilute Captan

A major problem I've encountered is damping-off, with affects the base of the seedlings and causes them to rot. The fungicide Captan has proved to be an effective preventative. I have also read of a layer of perlite over the soil being used, as this reduces the moisture level around the seedling base where the fungus wreaks havoc. In my experience most commercial fine-texture seedling mixes work fine as long as they drain freely enough.

Seedlings from repeating parents can bloom very quickly after germinating.

Species or once-bloomer seedlings take years to grow before they bloom, but seedlings from reliably repeat-blooming parents bloom in the first year.

For the species, propagation via seed is preferred since each seedling will be genetically distinct. Seedlings of roses with complex pedigrees will usually be inferior to their parents and may exhibit significant visual differences-- the facet of mystery is what makes raising them so fun, even though the seedlings will likely only be of value to you.

Starting Out With Drosera

Drosera, or sundews, could very likely win a contest for the most Seussian plant. Whimsical leaves, often brightly pigmented in good light, with tendrils dripping with digestive dew, are the main attraction of this carnivorous genus. To get started with this group of plants, I chose the "easiest" species, D. capensis and D. spatulata, which can be grown in a tropical terrarium. 

Drosera spatulata, without dew at the moment

Since these two can hybridize freely, perhaps I can attempt a cross when they flower simultaneously. But for now I'll just work out the basics of sundew culture-- although I suspect there will be future additions!

Euphorbia's Morphological Bonanza

It has occurred to me that I have a tendency to rant on about how Rosa has such an impressive amount of diversity. But looking at morphology, most roses are really very similar-- generally all have compound leaves, prickled canes, and five-petalled flowers in a small range of colors.

In a greenhouse the other day, I saw two very distinct plants-- the common poinsettia, and the houseplant known as "crown of thorns." Well, admittedly, there are easily discernible commonalities between them-- but you get the picture. These vastly different plants are in the same genus, Euphorbia.

Yellow-flowered Euphorbia milii

The classically thorny shrub, fierce and exotic looking but quite easy to grow

Red-flowered Euphorbia milii

E. pulcherrima, the wild parent of ornamental poinsettias (photo credit).

The morphological diversity is especially evident once you include the succulent euphorbias.

E. squarrosa (photo credit)

E. globosa (photo credit)

E. frankiana (photo credit)

Some grow as rather large shrubs:

E. cotinifolia (photo credit)

Just mindlessly skimming over these photos, it doesn't look like the plants are at all related, but in fact each is the same genus-- a degree of morphological diversity that roses certainly can't compete with.