This week we visit River Farm in Alexandria, Virginia. River Farm was, at one time, one of four farms owned in the late 1700's by our first President, George Washington. Today it is home of the American Horticultural Society and has beautiful naturalistic and formal gardens featuring flowering bulbs, trees, shrubs and ornamental grasses.
Peggy Bowers is the horticulturist in charge of this beautiful, historic property and today shows Charlie River Farm in early Spring. We first look at Daffodils in the maze garden. They are a good example of planting bulbs in mass. There are different varieties of Daffodils, some are early bloomers, some mid bloomers and late bloomers. By planting different varieties it extends the season of color. It is also important to plant a lot of bulbs, it makes an impressive show. In this bed Peggy planted 1,300 bulbs. She used different varieties, different colors, different forms, some are trumpets, some are doubles. For a dramatic effect plant all one variety, for a subtle effect plant different varieties, doubles and singles and some variations in color. That adds to the intrigue in a bulb bed.
Peggy has also planted bulbs with perennials. One bed has Daffodils, Wood Hyacinths, which bloom a little later, then upfront Daylilies. Daylilies are great companions to use with Daffodils, their foliage will hide the Daffodil foliage as it starts to turn brown and look ugly. That is an important tip with any bulbs, Tulips, Daffodils, Hyacinths, after flowering the foliage needs to yellow before it is cut back. The temptation is to cut it back after flowering but the plant needs to rejuvenate itself for the next season.
Peggy has had some Deer damage to some of her Daylilies. Daylilies and Hostas are Deer favorites, they nibble the tops off. The nibbling at this time of year shouldn't affect the bloom, they will continue to put up new foliage. It is difficult to control Deer. Peggy uses a combination of dried blood and mil organite which also acts as a fertilizer. This does a fairly good job with the Deer but it all depends on the size of the herd, thus their appetite. They don't seem to like the smell. The most effective method with Deer is probably fencing, possibly even electric fencing if appropriate.
Squirrels are also a problem. They like bulbs, Tulips, Crocus are some of their favorites. They will pull them up as fast as you can plant them. They cause problems in the Spring or even when the plants are in full bloom. To control squirrels Peggy uses a wired cage or wired netting on top of bulbs. Cayenne Pepper also will act as a deterrent. When they get a nose full they don't seem to want to dig in that area again. Squirrels don't seem to go after Daffodils, however. To combat Squirrels plant resistive varieties, like Daffodils, use repellents but use them early in the season before Squirrels become a problem. Once they find something good to eat they keep coming back.
Peggy has some unusual bulbs as well. Puschkinias have a beautiful light blue flower. They are not a bulb often seen but are readily available and are early Spring bloomers. They come out about the same time as Crocus and are an nice compliment to Crocus and Snowdrops. The length of bulbs flowers is dependent on the temperature, the cooler it is the longer bulbs last, an 85 degree day can spell an end to bulbs blooms. Puschkinias are called Minor Bulbs. This can mean that the bulbs are unusual or they are smaller bulbs. They are great for putting in naturalized areas. Crocus is another bulb with an unusual color and shape. This Crocus, Gypsy Girl is an early spring flowering Crocus. It is blooming a little later this year because it was planted late last Fall. Oftentimes if a plant is planted a little late it may come up a little late. The general rule is-first year bulbs will bloom about 2 weeks behind other bulbs. Because it is getting established it takes time to get roots established into the soil. Normally the second year it will bloom on time.
Planting bulbs in containers is good if space is limited. Peggy planted a pot of red Tulips, they are Darwin Hybrids. In another pot she has planted Daffodils and underplanted with Violas. The Daffodils are both doubles and singles. Peggy thinks singles hold up better, they show their heads off better. The doubles are so heavy they tend to flop over, they really suffer in a storm. That is a great point, particularly in a container, if you get the smaller varieties, like the Little Narcissus, they are fragrant and they have such small flowers that they'll stand up better. Peggy planted these containers last Fall. She shows us how. First select the bulbs. If they have new growth and are solid when squeezed that most likely is a good Daffodil, a good bulb. If it is soft, toss it. To plant the container, fill it with soil so that the soil is about 5 inches below the top of the container. Place the bulbs very, very tightly together, they will touch. This will provide a full look. Even though they are close together they will still get enough nutrients and fertility to grow. They have nutrients stored inside the bulb. Once the bulbs are placed then put some potting soil, something lightweight, on top. Always use potting soil with containers, that will ensure the soil will be well drained and water doesn't sit because that will rot bulbs. Fill the container to the rim with the potting soil. Pack it down a little. Since this activity would be happening in the Fall the container will then be stored for the winter, probably in an unheated basement or by the side of a building with mulch around the top. Bulbs like winter temperature but don't want to freeze. In the Spring bring them outdoors, put it on a deck, on a patio, line your steps with it, it is great way to add Spring color.
Adrian Higgins is the extraordinary garden writer for the Washington Post and shares with us his tip for cutting back Ornamental Grass. Spring is late in Washington this year which is good because we haven't gotten around to cutting back our grasses. This is a vital late winter chore because if it isn't done before new growth emerges, cutting could damage the new growth. Different people have different techniques depending on the grass and tool. Adrian doesn't like to use pruners for this task he thinks they're dangerous in this situation. He likes very sharp hedging shears. He gets very low, maybe a couple of inches from the crown and starts cutting with a vengeance. He doesn't worry about being tidy because he can always go back and give it another haircut. With this Panicum he has tied it up so it is already bundled. He cuts away, not worrying about a clean edge because the new growth will come through and hide any imperfections. If one wants they could go back and tidy up but after it's cut it's ready for Spring. Thanks Adrian for your advice. We receive many questions about cutting Ornamental grasses each year, this is helpful advice.
Peggy and Charlie now look at some old trees. One is a Franklinias named after Benjamin Franklin another is an Osage Orange Tree. It is a native tree, native to the area West of the Mississippi and was used extensively by the settlers as a hedge row, a living hedge fence and is often called Hedge Apple. An old tree like this needs pruning and supporting to keep it in really good shape. For a tree like this hire an arborist, they can evaluate the tree and decide whether to prune it or cable it. They have done both on this tree. Selective pruning was used to thin the branches to remove some weight. Cabling was used to provide support. They want to preserve this tree for future generations. This tree isn't called Osage Orange because it is like a tree in Florida, rather because the wood inside is very orange and very strong smelling. It does produce fruit. There are males and females, this is a male. The female produces fruit that weighs about 3 pounds and the size of a grapefruit. Charlie likes a male tree because they don't drop fruit all over the ground.
With a tree like this there is a temptation to plant things underneath the tree. Grass doesn't grow well because the roots are near the surface and because it is shady underneath. Grass doesn't like shady areas. A great alternative is to plant Hydrangeas, bulbs, Hostas and Ferns, as well Peggy has mass plantings of Helleborus Foetidus. A plant like Helleborus was chosen because it seeds itself and has seeded into a solid mass planting. It could not have been done mechanically. Instead of trying to force planting lawns or high maintenance ground covers under a tree use plants that are adapted to the environment, to the shallow soils and the shade. By doing that you'll have less maintenance and the tree and plants underneath will do much better.
Most people don't have an old tree like this instead they're starting fresh with a new tree. They now look a a new tree and show us how to prune them and keep them growing their best. When selecting a tree find one that will suit the site, find one that works where it will be situated. Consider ultimate size and growing conditions, is it a flowering tree, a Deciduous tree, an Evergreen, etc. They look at a good sized Maple. It has been in the ground two years and was purchased as an 8-10 foot tree, a fairly good sized tree. They wanted some shade in this area. That is an important point if you want an instant landscape, spend a little more money and get a bigger tree. That way you'll get the shade you want almost instantly. If money is a consideration start with a smaller tree. You'll need to be a little more patient but it will grow. This tree does need some corrective pruning. It has some crossing branches and there are some poor or tight crotches which will weaken the tree. Trees like this, if not pruned, are more prone to storm damage, heavy winds, snows which can lead to diseases getting into your tree and causing rot. Many times trees aren't pruned when they are younger, then later on they have poor, weak branch angling. A windy storm or heavy snow and a whole limb comes down and deforms the whole tree. They first look at branches that are crossing or rubbing each other and take those out. With branches with really narrow crotch angles take the back branch out. Look at the form of the tree you're going to leave once the cut is made. Envision it with one or the other branches missing and decide which one is going to give an open canopy, a better form. Look at your tree from a 360 degree angle so you can see that the branches are spaced out properly and the look is what you want. Winter or early Spring is the best time to do this because without the leaves it is easier to get a better idea of the form of the tree. After pruning, the tree is more open, thus more light can get in and air circulation is better.
Next they talk about mulch. There is a right way and a wrong way to mulch. Peggy and Charlie first show us the wrong way. Never put your mulch right up against the tree, leave some space. If up close it creates an environment where the base of the tree could actually rot. Lately we've seen the mulch piled up really, really high next to the tree, they call that volcano mulching because it looks like a volcano is at the base of the tree. This can suffocate the roots and interferes with oxygen getting through to the ground. This is the wrong way. Instead pull the mulch away from the trunk of the tree, you want an air space in there. Usually 2-3 inches away from the trunk is good. Then add about 2-3 inches of mulch around the tree evenly. Ideally the larger the mulch ring the happier the tree. This may not work with a lawn situation, however.
If in a Southern area where the mulch decomposes quickly you may not need to remove the old mulch. In Northern climates the mulch will keep building up so in the Spring remove the old mulch before putting on the new.
Peggy and Charlie next look at a beautiful flowering tree, one of the first blooming in the area. It is a Cornelian Cherry or Cornus Mas and is a great early Spring flowering tree, one of the earliest to bloom in this region. It will grow to about 20-25 feet in height. When growing these flowering ornamental trees a nice place to put them in the landscape is against a backdrop of Evergreens, like the American Holly. Put them on the edge of your property, they do well in part sun as well as full sun and because they have the dark green backdrop the flowers will show up much better.
Another yellow flowering plant is Corylopsis or Winter Hazel. they're not widely used but are available. It will grow to about 6-8 feet tall and it puts on a great show in the Spring. After that it is just pretty much a little green shrub that hides in the background or on the border. A good idea to keep in mind when selecting a shrub for a border is to select a variety that is smaller or a dwarf variety. That way you get all the characteristics of the flowering shrub but one that fits your location.
Charlie says he likes fragrance with his flowers so Peggy shows him a Mahonia Aquifolium. It has beautiful flowers but it doesn't have the sweetest smell. It will grow in full sun to partial shade, it has beautiful yellow flowers on it late winter through early spring. It has burgundy foliage that lasts all Winter into Spring. It is drought tolerant and bees and pollinators love it. But the smell isn't fragrant.
Peggy now shows Charlie a Daphne Odora. It has a wonderful scent and is a fragrant shrub for Winter, early Spring. It needs afternoon shade and perfect drainage. It blooms late February through the first of April in this climate, zone 7. Try it underneath a window, near a porch or walkway so you can enjoy the fragrance as you go by during the cooler, not so pleasant, outside months.
Thank you Peggy for showing us River Farm.
American Horticultural Society
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