Garden Notes for May
Oh, the garden, where to begin? The three primary goals for this season of dryland gardening are to complete a second terrace, to improve our irrigation system, and to maximize the crops that take advantage of the spring moisture. Last year, we built the first retaining wall out of railroad ties and rebar. This year we decided to go another route--rocks. We debated this decision for considerable time; do the functional and aesthetic benefits of a rock wall outweigh the labor involved?
When we finally decided the rock wall was what we wanted, we first set out digging a trench. Since the garden is sloped in two directions, north to south and east to west, the trench serves as the "level" line from which we build up and provides some stability to the wall. Then, it was a matter of rock hunting. Carina, Marylou, Sarah, Theresa and I have spent several days over the past month gathering large rocks from around the property and bringing them to the garden using a hand cart, a ramp, and a pickup truck. Some of the rocks we have incorporated into the wall are quite sizable and we even popped the tire on the hand truck while moving one of the larger rocks.
Once the rocks are gathered, its just a matter of fitting them together, which is a fabulous combination of a mental puzzle and a physical challenge. Its amazing to me that just given a pile of random rocks, they always seem to be able to fit together neatly. About 60 feet of the 80 foot rock wall is completed. Its the kind of work that I like to do for hour long intervals before my arms and fingers become too weak for safe and efficient work. I am now racing against the clock of those winter squash growing steadily in prop house, as they are destined to be transplanted in to region behind the still unfinished portion of the wall.
Last year, a good portion of the watering was done by hand. Two downsides to this are the time spent standing with hose in hand, and and water loss to evaporation. So, we wanted to move towards a system that required less time input and more efficient delivery of the water to the plants. In the past we have tried perforated soaker hose, but have not been overly pleased with its results. However, the PVC pipe with holes drilled in it that we use for the potatoes works remarkably well.
Since effective and efficient water delivery is such a key part of any summer gardening plan here, we decided to try a few options to see what makes the most sense for us. Over the past month we have been fiddling with two basic setups, one which is expensive and time consuming to set up, the other which is inexpensive (partly because we repurposed some old materials) and fairly easy to set up.
In most garden centers or big box stores like Home Depot, you can find flexible irrigation "poly tubing" which can be accompanied by "spaghetti" tubing and a variety of emitters to more precisely control the location and rate of water flow. It took several hours to set up one line of this poly pipe using the spaghetti tubing and emitters; it was a tedious and frustrating process, not to mention expensive. For the remaining rows we used 5/8 inch stiff black plastic tubing that had been in storage for several years and was no longer needed for its initially intended purpose. So we uncoiled this tubing, cut it to length, and experimented with hose connections until we found a system that worked (the irrigation tubing stuck inside a ~5 inch section of garden hose clamped with a hose clamp, and then a hose barb with a female hose fitting on the other end stuck into the garden hose). We poked small holes in the tubing using a nail and were able to set up several irrigation lines in a few hours.
So, now all the plants in the terraced section of the garden will be watered through the drip irrigation systems, which is a considerable step forward. One potential foreseeable issue is that the small drip holes will become clogged, but only time will tell. And as for the spaghetti tubing and emitters, this is a system that might be more appropriate for trees and bushes where the number of watering locations (and therefore spaghetti tubing and emitter locations) is far fewer. So we will likely put the remaining of these materials to use for the fruit and nut trees.
I think we have seen the last of the cold nights for some time as the warmer temperatures and longer daylight hours combine to create a flurry of growth in the garden. The salad greens have been growing steadily, and have almost reached the point where the production out paces our consumption. The radishes, planted in with the carrots, are doing double duty--keeping down weeds and adding a pit of spice to the salads. The brassicas, are doing great; we have a variety of cabbages, broccoli, kale and collards that are enjoying the relative cool of the spring. The turnips are going crazy, as usual; every day we thin them out, and the next day they have grown to fill the gaps. The beets and parsnips and rutabagas are all growing happily and soon the thinnings will appear in the noon-time salad. The peas are growing well now, though the attempts to get peas in early just translated into slow germinating times (1 month) as the soil was still too cool.
It is also time now to get the warm weather crops in the ground. An early variety of sweet corn went in the ground about 2 weeks ago, and the Oaxacan corn was planted a few days ago (since corn cross pollinate, it is important that these corn varieties flower at different times, hence the staggered planting schedule). We will continue experimenting with peanuts this year, a Valencia and Virginia variety. We are also testing out the staggering planting of broccoli and corn. Broccoli and cabbages are a relatively low plants that enjoy the cool, corn grows tall and provides quite a bit of shade, so we have tried planting corn between the already established brassicas in the terraced beds. In addition, in a few of the large tractor tires, we have corn planted as one of the three sisters. We recently transplanted the peppers and tomatoes, seeded the okra and first round of green beans.
As usual, all plantings receive a healthy amount of mulch to keep weeds down but more importantly to retain soil moisture. The squash, cucumbers, basil, and sunflowers all still need a little more time to grow before they will be ready for transplanting. Up in the spiral garden, which is quickly evolving into a garden of perennials, the asparagus planted last spring is doing great. Some of the shoots sent up this year looked large enough for harvesting, but we decided to refrain from the feast as to let the plants give more energy to establishing the roots.
The rhubarb is enjoying its new home and has leafs large enough to make you think we are in the understory of a tropical forest. The sunchokes, or Jerusalem artichokes, are finally poking up above ground too. May 17: The Grafts Leaf Out As I have mentioned in the notes before, over the past year and a half I have been practicing grafting fruit and nut trees. One of the reasons plants are so remarkable is that many plant cells are totipotent‒they have the capacity to differentiate into any of the array of more specified cell types (such as a root cell, which is structurally and functionally different from the cells in leaves or the cells that make up xylem and phloem&8210the transporting "veins" of plants). The critical step in this process is performed by a cell called a callus cell--which refers to an undifferentiated cell that can grow into any cell type if the appropriate conditions are present. Plant lovers over the millenia have taken advantage of this characteristic of plants to aid propagation of specific cultivars and varieties of perennials. In grafting, it is the formation of callus cells and then the more specialized cell types that these callus cells differentiate into near the wound caused by the grafter's cut that enable the graftwood and the rootstock to physically bind to eachother and ultimately function as a single plant.
This is all well and good in theory and botany textbooks go into more detail about the biology of it all, but to actually create these conditions with nothing more than your own two hands, a knife, some plastic, and of course the plants themselves is another task all together. In order for callus cells to form and the graft to be successful, the conditions have to be just right--and the graft will fail if indeed just one of these conditions is not met. Grafting, amongst other things, is quite time sensitive; there are two times of year when it can be done, and so over the past 18 months I have made three different attempts. Only the grafts I did this past February and March-- the third and most recent attempt--were successful. Grafting is one of those tasks that requires quite a bit of practice before it can be performed consistently well. One of the nursery folks I learned from said that the first time you try grafting, be sure to make many grafts as you will be lucky if you get one to take and so the more you do, the more you increase your odds at being succesful. This was good advice. Grafting has also reinforced for me the value of patience and importance of local knowledge. You can't rush such processes as cell formation and thinking back to the first few grafts I did last year, I may have given up on them too soon. Also, there is little of more value when learning such a precise task than the advice of those that have successfully grafted in the local area. Local climates can vary considerably, especially in mountainous areas, and timing is quite critical when it comes to such botanical endeavers. In the same vain, it is important to seek advice from folks that work under similar conditions as you do--in my case this means without a heated greenhouse or large refridgeration spaces. I am lucky enough to have been able to talk with and obverse the Klicktiat arborist who plants and tends to all the fruit trees in town.
So, I haven't made a precise count yet, but my best estimate is that this most recent grafting attempt with the apples had about an 80% success rate. To see if the location of the rootstock impacted the results, I potted up a portion of them in Vermadise where they have remainded since, while the majority were planted outside. It does not appear that there was a significant difference in success rates between the two locations, with the primary difference being the plants in Vermadise began leafing out earlier--likely due to the warmer temperatures. The steps that I took for grafting the apple trees are as follows:
I also have tried grafting English walnuts onto Black Walnut rootstock, but this is a bit trickier due to the juglone that walnuts emit that prevent callus cell formation. Sources recommend cutting the rootstock 10-14 days prior to grafting so as to allow the the juices containing the juglone to bleed out. I followed this advice but only had a handful of rootstock of appropriate size for the scion wood and there appears to be no acitivity yet in the scion wood. Also, I tried grafting some plums, using rootstock from naturalized plums and scion wood from a more cultivated variety, but again, the buds of the scion wood have yet to swell and I imagine this means I will have to wait another year to give grafting plums another try. |
