Summer quarter is the time for Hort students to get out in the arboretum and make a difference. They develop weed management plans, edit beds, water, mulch, cardboard mulch, prune and weed. For some of them this is the end of a fulfilling yet challenging year in horticulture. Thank you everyone for all your hard work!
A favorite part of the summer curriculum is traveling to botanical gardens, estates and grounds and looking at plants. No matter what age, students never get tired of taking a field trip. Chateau Ste. Michelle in Woodinville is no exception. Gazing at the beautiful mature trees, identifying perennials, trees and shrubs and critically viewing the lawns as we discuss sustainable lawn care adds to the knowledge and experience of horticulture students. Lucky for us this amazing place is just around the corner.
Now that the hectic pace of spring has come and gone, it's easy to think that all the hard work is over. The planting, fertilizing, trimming and clean-up are all complete, shouldn't we just sit in our Adirondack chairs and gaze serenely at the garden? We can't forget one of the most difficult tasks a gardener faces, summer watering. With our Northwest summer drought, plants need consistent and thorough watering to grow and stay healthy.
I'll never forget a Myrica californica that is growing in the arboretum. When I first noticed it a few years back it appeared healthy. The leaves were green. It had new growth, but it was small. We added irrigation to its bed and within a year it had doubled in size. After two years it has tripled in height and width. It's a changed plant now, like it has a new breath of life with regular and consistent watering. I see its potential. It's interesting that we might think a plant is doing just fine. It's green. It grows a bit every year. And then suddenly when all its needs are met...wow! It can take off.
There are many methods available, sprinklers, watering cans, drip irrigation and in-ground irrigation systems with timers. Water is a precious resource and we should always be thinking about conservation. Setting up a home irrigation system such as drip irrigation may seem complex, but is really quite manageable. The main thing to remember is that plants prefer a thorough deep watering to a light superficial sprinkling. When we spray the surface, the soil may appear dark and moist, but underneath the roots have no moisture. We have to allow time for the moisture to reach the root zone. Water when the soil dries out, more often when it's hot and less when it's cloudy and cool.
It's happened so many times. I think I've watered a container really well, whether a small four inch pot or a large patio container. I might have to dump the soil out or dig into the container, and I'm shocked to find out it's dry at the bottom! A good method is to water a container until the water runs out of the bottom. I also like to give a container as much water as I think it needs. And then do it again. Give it twice as much. If the soil is too dry it can become hydrophobic and it takes a long time to absorb the water. Then the container will have to be watered two or three times. Over-watering can be a problem too, but only if the soil constantly remains wet and is never given the chance to dry out.
Planting similar groups of plants together can also help conserve water. Annuals and big leafy perennials take more water than established shrubs and trees. Keeping them in separate beds will make watering easier. Many of our Northwest native plants are tough and drought tolerant, but remember this is only after they have had a few years to grow a good root system. So when you add any new plants, even if they are 'drought tolerant', remember to water for the first two summers. Mulching is a good idea as it helps retain moisture. Rhododendrons are usually ignored all summer, but these plants will really benefit from a consistent supply of water. Remember, a healthy plant that has been well watered and fertilized will more easily fight off insects and disease. Just like us, if we aren't getting enough sleep or eating well we tend to get sick. So enjoy your summer garden and don't forget to give your plants a drink. And then do it again.
Blueberry: The best of Northwest summer snacks.
Vaccinium: Name of berry shrubs, including blueberries, cranberries, huckleberries and the elusive farkleberry. Of the family Ericaceae.
Corymbosum: With flowers in corymbs (a flat topped flower cluster, or inflorescence, with the oldest flowers at the periphery).
Deciduous Shrub: The leaves turn beautiful shades of red in autumn and drop off for the winter. It's okay, they'll come back.
Leaves: Alternate, ovate, short stalked, entire, pointed at both ends, leathery. Just a leaf.
Stems: Yellowish with an unassuming zig-zag.
Buds: Vegetative are narrow and conical like a leaf, flower are scaly, rounded to ovoid, like a fat flower.
Flowers: The lovely Ericaceae flower group, urn shaped, white to pinkish, May to June.
Fruit: The very merry berry. Green changing to blue (unless you get the odd not blue variety 'Pink Lemonade') Develops on spurs (shortened, compressed stems). Tasty, nutritious and wholesome.
Height: These plants usually reach 5-6 feet and can be just as wide. Depends on the variety. There are smaller container options available like 'Top Hat', 'Sunshine Blue' or the blueberries in the Brazelberry Collection.
Key ID's: Leathery leaf, yellow zig-zag stems, fruiting spurs.
Light: Sun to part shade. More sun equals more fruit.
Blueberry: Grow them, eat them, share them, and enjoy them. An exceptional plant.
Integrated Pest Management doesn't stop in the summer months here in the horticulture department at LWTech. Purchasing may pause, classes may take a break, but the plants grow on, ignorant of the fiscal year or the academic calendar. We have over fifty stock plants potted up in 5 gallon containers that we are growing to use for cuttings next Fall. It's really incredible that from one bacopa plant we can propagate over one thousand four inch plants simply by taking cuttings. The trouble with growing stock plants now is the dry summer environment. It gets hot. They dry out. Long weekends occur. They dry out. They wilt, they come back, they fade, they grow. All this puts a lot of stress on our unfortunate stock plants. Maybe a few get missed on fertilizer and growth stalls out. They could outgrow their pots, which creates more challenges with watering. It's definitely a tough life for these stock plants. We do put a few in the ground in the arboretum, but in general most are in the covered area in front of the greenhouse.
As the plants stalwartly make their way through June, July and August the insects find them, like them and decide to stay. Currently in our little zoological garden we have foxglove aphids, greenhouse whitefly and western flower thrip, all living on our beautiful stock plants. This year we are focusing on plant health and beneficial insects to help our stock plants thrive. Regular inspections, pruning and clean-up will help us. We can't find out what's wrong if we don't take a close look. Also diligent watering is a must. More in times of heat, less when the skies are cloudy. When an insect pest is discovered, we like to flag that plant as a reminder to monitor it. It's easy to forget which plant has which pest when there are so many, so some type of tracking system is necessary. We use different color flags for specific pests. Then if you look out over the crops and see a cluster of white flags in one area you know that there is a problem and that specific pest may be spreading.
The beneficial insects that we use each have a specific prey that they attack. The tiny parasitic wasp Encarsia is used against whitefly, laying eggs in the young whitefly larva and eventually killing them as the new adult Encarsia emerges. These are not wasps for humans to fear however, they are less than one millimeter long and they don't sting. The complete life cycle for an Encarsia wasp is only 28 days. We also use tiny mites to attack the larval stages of thrips, another parasitic wasp, Aphidius, for aphid control and the generalist beetle Orius for thrips, mites and aphids. On the surface everything appears calm, but under every leaf there's a battle going on. We hope our plants can win! If you have any questions about beneficial insects or our IPM program, please contact us at firstname.lastname@example.org.
Wreath making has arrived! When November rolls around students learn how to look at plants in a whole new light. Instead of thinking about landscape usage and sun or shade conditions, we think about bling and flair, color and texture for a holiday wreath. It starts with collecting the bones of the wreath or the green boughs that will make up the major portion of the wreath. For this we use Leyland Cypress, Douglas Fir and Western Red Cedar. Luckily a windstorm recently swept through Western Washington and we benefited from windblown branches that had been knocked to the ground. These are great because they are from the top of the trees, have received lots of sun and have nice full growth. Good wreath material! After collecting the greens, we scour the campus and surrounding areas for accent plants. Holly, Beauty Berry, Karl Foerster Grass...anything that provides a touch of individuality to the wreath. Students learn that many of the plants they have been studying all year can combine to make an amazing wreath. Nothing is better than presenting loved one with a wreath made from xCupressocyparis leylandii, Gaultheria shallon, Psuedotsuga menziesii, Lanvandula angustifolia, Corylopsis pauciflora, Cornus sericea and, of course, Callicarpa bodinieri, a class favorite. Wreath making has become a favorite Horticulture holiday tradition.
This Fall our students have a special opportunity to learn about the world of irrigation. With the help of Cascade Water Alliance and instructor David McGrath, the students are using the irrigation learning lab in the arboretum to understand equipment, repairs and control settings for a standard system as well as a drip system. We hope to continue to use the irrigation lab to train our students as well as other local industry groups. On this day students learned how to adjust a sprinkler head so it sprays water in the right place. They also adjusted the placement of a sprinkler head that was several feet away from the bed, bringing it closer with a funny pipe and new fittings. Finally students learned how to deal with a broken pipe, cutting out the leaky piece and gluing together the new parts. As students become familiar with the different parts of an irrigation system they are better prepared to make repairs on a job or install a drip system in their own yard.
This week in class students acted out the growth of a tree. They became cork, cork cambium, phloem, vascular cambium and xylem as they transported sugars, created new cells, protected the outside of the tree and moved water. Now they will never forget what is going on inside of a tree!
Horticulture students have many talents and this year they produced a bountiful harvest of fruits and vegetables. Every summer students are given the opportunity to grow a garden in the small plot and grow boxes on the West side of the greenhouse. Even though we discuss growing vegetables in our classes, the summer garden is independent of the curriculum. Students form a garden team and plan what they will grow and take full responsibility for the care of the garden all summer and into the Fall. They often start seeds in the greenhouse in May and transfer the seedlings to the beds by June. The weeding parties begin then and by hot July and August they are diligently dividing up watering duties. August and September still have a lot of work as they harvest and then begin to clean up and prepare the beds for winter. This year they grew squash, watermelon, beets, peppers and a never-ending supply of Sungold Cherry tomatoes. After the students took what they needed for their families, the remainder of the harvest was donated to the local food bank. For some it's their first time to grow vegetables. Working with others and receiving advice from the horticulture staff, they receive a valuable education and are ready to continue growing food in their own gardens in the years to come.
This week as we study greenhouses we had a terrific field trip to T & L Nursery in Redmond, Washington. The general manager Andrej showed us through the shipping area, the propagation house, the old and the new greenhouses as well as the extensive outdoor growing area. It was fascinating to learn about the history of the greenhouses and how each one serves a specific purpose. Some are for warm growing in the winter, others just to keep rain off plants in the spring. We saw vents and side flaps, heating and cooling systems, irrigation and learned about the computerized environmental control system. Everyone enjoyed getting an inside view of this very successful nursery, which is in our own backyard!