Saving Seed

There’s nothing like a cold winter day to get you thinking about spring. So last weekend when it was 2 below zero (still zone 6, see previous blog entry) I did a seed inventory. I was about to start filling out an order from my favorite catalog when I realized that I still had a lot of left-over seed. So I sorted and evaluated my stock. Wow! Do I ever have a lot of lettuce seed! Some of it from 2005.

The question is: will that seed still germinate? It depends on the species and the storage conditions. In the case of lettuce, my references say it is one of the best at remaining viable… maybe 5 years under good conditions. My left over onion seed from 2003 on the other hand, is mostly dead.

What are good storage conditions? In a nut shell, cool, dry and dark. About 40 degrees F and very low humidity. Temperatures in your fridge are fine; the enemy is moisture. Sealing dry seed in air tight jars with silica gel packets or another moisture absorbing material is best. Dry powdered milk might be handier for many of us than silca gel. Just put a couple of tablespoons in tissue paper, seal with rubber bands and add to your airtight seed storage jar.

Is that how I store my seeds? Sadly, not. They’ve just been in the garage… dry but subject to a range of temperatures and fluctuating humidity. So I’ll lower my expectations. Experience tells me that for most species, germination percentage may be down but enough of the seed is viable enough to warrant keeping it. Just sow a bit thicker than with fresh seed. If I had the time (or if the stakes were higher)I’d do a germination test by putting seed on moist paper towels at room temperature and recording the percentage that sprout. I probably won’t get around to that either.

Ok, here’s what the books say about seed longevity under good storage conditions. 1 year : onion, parsley, parsnip. 2 years: okra, pepper sweet corn. 3 years: bean, carrot, pea, broccoli, spinach. 4 years: beet, cabbage, cauliflower, eggplant, pumpkin, tomato. 5 years: collards, cukes, melons, lettuce, radish.

Note that what happens is that germination percentage declines over time. They don’t all die at once. And storage conditions have a big effect. One reference I read described seed of many vegetable species with germination rates over 50 % many decades after being put into ideal storage.

How Cold Was It?

That’s a question that gardeners and farmers ask each other all of the time. The talk really heats up at several key times of the year: mid winter, when extreme low temperatures occur; late spring, when frosts can damage tender new growth and blooms; and again in the fall, when the first “killing freeze” signals the end of the growing season.

It is supposed to get a bit chilly later this week so I am sure there will be lots of conversation about the season’s lowest temperature, to date. The weather women (a major improvement over the weatherman) are talking about single digits on Thursday and Friday nights. Since most of Bucks County, PA is in USDA Hardiness Zone 6, that’s normal. In fact, if temperatures stay above minus 10 degrees F we are still within the normal average range for zone 6.

If you are not familiar with the concept of hardiness zones, click on the USDA link shown above and educate yourself. Zone designation is based on records of average low temperature that occurred from 1974-1986. The country is divided into 11 zones. The lower the number, the colder it gets.

Believe it or not, there is weather outside of the USA. I recall taking a stroll in Skibbereen, southern Ireland, a few years ago and admiring the Fuscia hedges. They were obviously hardy perennials there. This is Zone 9. The locals said it rarely went below freezing. The hardiness map says the average low temperature range is 20-30 degrees F. I note that my gardening pals in Nuremberg, Germany are zone 6, just like us. I would expect that the procedures I use for growing garlic would work there as well. Cold hardiness is a useful, international concept.

However, cold hardiness is only one important factor in plant growth. For instance, although the average low temperatures in southern Ireland look good for figs, I wonder if they get enough heat to ripen a crop. Rainfall, day-length and many other factors play a role in plant survival. I’m told that although Norway Maple is cold hardy in the southern states, it struggles under the high temperatures. Same thing with currents and gooseberries.

There isn’t much you can do about the weather but it’s important to consider winter hardiness when deciding what plants you are going to grow. Professional horticulturists and plant sellers use the USDA hardiness zones as an official and useful guide.

Of course, gardeners are always pushing the limits. I’ve got a fig tree and crape myrtle in my yard and they are both of these are zone 7 plants. I expect them to be severely injured by low temperatures now and then. Both have been killed to the ground. They re-grow from below ground parts that were not exposed to the killing temperature. Pushing the limits of hardiness zones is OK for the amateur but you’d be nuts to start a fig farm in zone 6.

Caring for your Cut Christmas Tree

Christmas trees are a wonderful part of the holiday season. Although artificial tree have taken some of the market away from “real” trees, still, millions of homes display real trees each year. Got mine yesterday and I was reminded of several things….they aren’t that expensive, they’re easy to put up, your wife thinks it’s great that you did it and they smell and look wonderful. If you want some more reasons real trees are a good idea, see the folks at the National Christmas Tree Growers Association. Sure, it’s their product but the website makes some great points.

On to real tree care…. for some reason people want to make tree care more complicated than it needs to be. Penn State Christmas tree specialist Rick Bates dispels many myths in a handy fact sheet. In a nut shell, keep plain old water in the reservoir of the tree stand at all times and everything is OK. Both Penn State and the Christmas Tree Growers think the fire hazard from Christmas trees is way overblown. I recall a very unscientific study my graduate school advisor (and Christmas tree grower) and I did one year in January. We tried to ignite dried out, discarded Christmas trees with a lighter. No luck. I am sure someone has done a better job demonstrating how hard it is to make them burn.

How about tree disposal? Many townships will help you turn that tree into chips. Or do it yourself with a pair of loppers. It takes five minutes to turn your tree into mulch. Ours becomes a bird sanctuary and lawn ornament until late winter.

Holiday Shopping for Gardeners

By some estimates, gardening is our nation’s number one hobby. I believe it. So, gardening gifts make a lot of sense. It helps to know your gardener… are they into flowers, vegetables, woody plants, container gardening? Do they have a special interest such as orchids, bonsai or fruit trees? Here are a few shopping hints.

I just took a quick look at the on-line gardening companies that I buy from. They all offer gift certificates. If you don’t know exactly what your gardening friend needs this ought to work. Rummage through the gardeners’ catalog pile at home (all gardeners have one) and you’ll know where to begin. Local nurseries and garden centers would be happy to have you business, too. No doubt you’ve been along on one of those trips and know where your friend shops.

Pruning is a common practice for all gardening. Pruning tools range from saws and loppers to tiny hand shears. Felco, is a Swiss company that sets the standard in this realm. I notice that they offer 16 different kinds of hand pruners. Wow.

If your gardening friend has everything he/she needs or you just want to do something a bit different, consider planting a tree in their honor. Local arboreta, townships and garden clubs can probably help you get that tree planted. Or try arborday.org.

Last but not least… Penn State Soil test kits make great stocking stuffers. They cost nine dollars and are available at any extension office. Or go to www.aasl.psu.edu to see how to do it on-line.

If a trees falls in the forest..

If a tree falls in the forest and no one is there to hear it, does it make a sound? I won’t get into that philosophical question but I recently spent a few days in a forest and had time to make some observations that made me think about tree mortality.

At Penn State Extension, we frequently get questions about why a particular tree has died or is dying. Sometimes we can attribute an insect or disease pathogen to the problem. However, almost all tree mortality is a complex situation involving environmental stresses as well as destructive organisms. Many people want a simple answer (and solution) about tree death but usually the story is more complex and does not have a simple diagnosis or treatment.
What struck me as I sat in the woods and observed trees was that there were a lot of dead and dying trees around me. Walk into any woods and look around. You’ll see the same thing…more or less. I don’t think this is unusual. It’s natural. Sure, there is explanation for most of it. I know that insect defoliation was involved in the death of some of the trees I was seeing. I know that competition for light was thinning out others. I could see lots of fungal pathogens. One species always seems to die at a relatively young age without apparent cause.

What does this mean? For me, it puts tree mortality in perspective. No one likes it when trees die and when important trees die, or die suddenly without explanation, we look for answers. Sometimes the diagnosis appears straight forward. For instance, hemlock wooly adelgid is the primary cause of hemlock mortality in the woods I was sitting in. And in this case, I think I was witnessing not only individual trees dying but perhaps the demise of our state tree as a species in Pennsylvania. More often, trees fail and exhibit a range of symptoms that lead to educated guesses about the cause. Most of the time that’s as far as our knowledge goes.
The suburban trees that we pamper and tend to in landscapes are subject all of the stresses as their wild forest relatives. It’s sad, but part of Nature’s way when they die.

Wrap that Fig

Holidays are good reminders for certain garden activities…. In Bucks County we think of planting tomatoes about Mother’s Day, seeding new lawns on Labor Day, planting garlic on Columbus Day. To this list I’d add… wrap you fig on Thanksgiving.

What? You don’t have a fig tree? Well ask around. You’d be surprised how many Bucks County gardeners cultivate figs. These exotic, tasty fruit ripen in late summer and are a real treat. The plants are almost pest free and require very little care beyond a bit or pruning and winter protection. I joined the fig club a few years ago when a Bucks County Master Gardener gave me a root sucker to plant. I am not certain of the variety but it is probably Brown Turkey which is reported to be hardy to 10 degrees F.

Winter protection really starts with site selection. Place figs in a sunny protected area, preferably against a southern exposed building wall. This alone will go a long way towards improving winter survival of above ground canes. Although I mentioned fig tree, the plants growth habit is more like a multi-stemmed shrub. Fruit is borne on current seasons’ growth.

So, back to wrapping. Is it necessary? Maybe not. The person I got my plant from lives in central Bucks County and provides no protection. For insurance, consider tying all of the existing canes together in a bundle and wrapping them with burlap or any other sturdy cloth-like material and them re-wrapping with a more wind protective material. I’ve used the cheap tarps commonly sold in hardware stores. Some folks wrap loosely and fill the center with insulating material such as straw.It's a two person job.

Finally, mound soil over the crown of the plant. Even if the top growth freezes out, you’re likely to get re-growth from below ground if the crown is protected in this manner. Since fruit is born on current sesons growth you’ll still get a crop, although not as much as when old wood overwinters.

I discovered this the hard way on my first fig growing attempt. I assumed the worst after an unexpected, early December temperature plunge to single digits left my plant unprotected. After tilling the planted area in the spring, I discovered that there was life after all, below ground.

For a fact sheet on growing figs in northrern climates, check out what the folks from Cornell University on Long Island have to say at this site.

Pennsylvania Horticulture Society Recognizes Master Gardners Efforts

An educational garden extraordinaire! This garden is the perfect location for a field trip for those anxious to learn about horticulture. There are displays of sun, shade, perennial, butterfly and pollinator gardens. So many varieties all beautifully labeled. Those well placed labels quickly resolved identification disputes. This Penn State Master Gardener Demonstration Garden provides a blast of color in an ocean of cold hard architecture.

That’s how the Pennsylvania Horticulture Society (PHS) described the gardens at Neshaminy Manor Center at the awards ceremony earlier this month at PHS headquarters in Philadelphia. We were one of about 75 gardens recognized in Pennsylvania, Delaware and New Jersey this year with the Community Greening Award. While Master Gardener coordinator Sue Schneck and I accepted the award, we both know that it is the hard work of dozens of volunteers who make it happen. The design, installation and management of these gardens is done by an outstanding crew of dedicated volunteers. Recently, we cleaned up dead summer foliage and planted pansies, so the gardens continue to look good. PHS folks must have missed it but our mini arboretum is part of our educational efforts and is functional all year long.
What is PHS? Just one of the oldest and most active horticulture societies in the U.S. Most folks know the Philadelphia Flower Show and sure enough, PHS puts on this popular event. But did you know that the proceeds from the Flower Show go to community greening efforts? Did you know that PHS has one of the finest horticultural libraries around? I spent an hour of so browsing the collection. Fantastic! They sponsor great lectures and other educational events. Check out PHS and consider becoming a member.