BATTLE OF THE VOLES: THE HISTORY





THE PLANT



Arrowleaf Balsamroot (Balsamorhiza sagittata) is THE iconic flower of the Methow Valley. It is a deeply rooted plant with showy orange flowers that blooms in early spring. The plants favor exposed steppe-shrub hillsides with relatively poor soil and good drainage. Balsamroot do not mature quickly - it takes about five years for the first flowers to appear. Iconic specimen plants in the Methow are estimated to be 30+ years old.




An iconic field of balsamroot. This is from the Ranch Annex, a adjacent property purchased in 2020, which is being used as a seedsource for the main Ranch.



Balsamroot have very long taproots (8+ feet long) and cannot be transplanted successfully from wildland locations. They also have germination inhibitors in the seeds, making them difficult to propagate by directly sowing seed. The best path for re-introduction we're found so far is to not re-invent the entire process of growing seedlings from seed, but rather to buy seedlings from an established source (for example Derby Canyon Natives, see link below). However, that is only the beginning of the process! This page describes some of the many challenges in re-establishing balsamroot even AFTER you've acquired healthy seedlings!





THE HISTORY



The Ranch has a checkered history of environmental management. The locals recall various historical attempts at cattle grazing, dryland wheat cultivation, weed-free grass seed cultivation, sheep pasturage and the like. One consequence of this is an almost complete lack of Arrowleaf Balsamroot on the Ranch compared to adjacent properties. Increasing evidence suggests the previous owner did large area spraying of some broad-leaf weedkiller - as balsamroots are starting to slowly seed back in from the adjacent properties, and none of them are older than five years or so. The process is VERY slow however, perhaps a total of 15 or so plants have seeded in naturally.




A great image of the impact of the long-term impact of land management. (This is the property next door to the Ranch, by the way). The fence posts on the left are the remains of the original (1950-ish?) fencing. (Today's property boundaries don't match the old boundaries, by the way). The left side of the old fence was likely cultivated more than 20 years ago, the right side was likely grazing land. Today, the balsamroot on the right of the fence has recovered fully, however the balsamroot on the left has not. However, if you look closely, you'll WILL see clumps of balsamroot (VERY SLOWLY) seeding over. Since it takes about 5 years for blooms - reseeding is a very slow process.



The long-term goal of the project is to re-establish a balsamroot population of about 25% the density of adjacent properties in the hope that is sufficient to recover the remaining population over time. This is now a two-tiered process, with one tier (from 2017 to date) being the establishment of pre-grown balsamroot seedings and the second tier (beginning 2021) with using seed from the annex to try and increase the number of "wild" seedlings




One of a handful of full-grown wild balsamroot on the Ranch. (This was taken April 2019, during bloom.)




THE VOLE PROBLEM



The montaine vole (Microtus montanus) just loves balsamroot seedlings and will uproot unprotected young seedlings (within the first night of planting, by the way). These voles remain active during the winter, and their characteristic "inverted" tunnels that appear right after snow melt (made from grass or mud that are a result of the voles plastering-up snow tunnels) are an indication of prime vole habitat. Unfortunately, prime vole habitat is also prime balsamroot habitat!





An example of "inverted" vole tunnels appearing right after snowmelt.



The solution to the vole problem (painful as it is) is to surround each new balsamroot seeding with its own personal "basket". The basket can be made from 1/4" hardware cloth (chickenwire does NOT work) and is staked with three or four stakes. The basket will remain with the plant until it is mature enough to resist voles on its own (probably 5 years).


Thankfully, the voles don't seem to be interested in digging under the baskets. As long as the basket is firmly staked AND there is NO hole ANYWHERE around the edge (AND no hole accessing the basket from below) the balsamroot seedings are protected from the voles.



THE VOLE SOLUTION





Young balsamroot seedling (the light green point in the middle) surrounded by an 8" basket. All four stakes can be seen (if you look closely).



4" Baskets



Unfortunately, the 8" baskets can be inconvenient to carry around at planting time (when many seedlings need to be planted in a very short period of time - more on this later), and we are experimenting with a two-stage process to aid in swift initial planting. In this new process, the initial seedlings are planted with a 4" basket, and that basket is then upgraded after a year or two with an 8" basket. The 4" baskets are enormously easier to manage, and the upgrading process can be done at a much more leisurely pace than the planting process.




Young balsamroot seedling (the light green points in the middle) surrounded by a 4" basket. All four stakes can be seen (if you look closely). Also note that the basket is planted in a location prepared for an 8" replacement basket when the time comes



WHEN TO PLANT



Balsamroot plants complete their entire productive season between the end of snowmelt and the 1st hot days of summer. Basically around April 1st to June 1st. They don't waste any time after snowmelt either - within a few days of the snow melting, the first grey-green leaves will appear. There are three basic planting strategies:


Spring: Obtain the plants as soon as possible from the nursery (April 1st is probably too late, even). Plant them instantly - in melting snow if at all possible. The benefit is that the ground is soft and the plants go in fast. The risk is that even a few days MATTER in this breakneck spring growth activity, and it is pretty easy to create a major disadvantage for the plant with just a few days delay.


Spring (after winter-over): Winter over the plants in a cold-flat and plant them as soon as the 1st snow melts. (This avoids having to sychronize the magic planting days right at snowmelt with the nursery.) The benefit is the plants go in fast and they are there on the magic first day of melt. The risk is loss of plants in the cold-flat over the winter. Our attempt at this in spring 2019 had a 60% yield, which is really low for plants in vole-baskets (90% is what we see for Fall-planted seedlings in vole-baskets). The failing plants appear to be rotted, by the way. If we do this again (and we probably won't, because it doesn't work very well) it may be better to leave the plants in the barn (where they will be cold and dry) rather than outside in a cold-flat (where they are cold and wet).





4" baskets, planted Spring 2019 after winter-over in a cold-flat. Yield was not good due to winter-over issues. A count on 4/15/19 showed a 60% yield, which is quite low. In vole-baskets we typically see 90% yield at planting. Root rot due to overly-wet conditios in the cold-flat is our present model.



Fall (right before snow). Plant right before snow in the fall. The plants are dormant at this time, so the timing risks are minimal. The benefits are both that the plants are dormant (giving much more time to get them in), and they will catch first melt in spring at just the right time (because they are already there). The risk is that the gap between first rain (when the ground is wet enough to be worked to plant) and first snow (when the ground is frozen) isn't very long either. We've seen 90% yield the following spring with this approach - and yield losses are virtually all due to basket-integrity issues. (The voles are active during the winter under the snow, and a loss of basket integrity, for example, by a deer stepping on a basket, means the loss of the plant.)





8" baskets, planted Fall 2017. Yield at spring 2018 was about 90%, and losses were all loss of basket integrity. Yield in Spring 2019 (counted 4/15/19) was also about 90% and 3/4 of the losses were also basket-integrity (deer stepping on baskets, snowmobiles running over baskets, and voles making holes into baskets). For this two-year window perhaps 5% of the total losses were something OTHER than basket-integrity failures.





8" baskets, planted Fall 2017. Spring yield is looking respectable, exact numbers in Jun 2019 (and this is a difficult location due to issues with the steep hill to the right, including deer traffic wiping out baskets, as well as voles being able to get under them more easily because of the slope.)



At this point, we favor Fall planting - it is less sensitive to exact timing and it has demonstrated the best yield so far.


HOW TO PLANT



For all these planting hints, it is assumed that you are planting in a wildland or semi-wildland setting, with limited access to water. If planting in the dry (for example late Fall, before any significant rain/snow), you WILL need some water, and a back-pack sprayer (like those used for weed-killing, but dedicated to water-only) can be used. With care, a single "filling" of the sprayer can do about 25 plants, so having back-up jugs in your truck is also a must if you are doing a larger quantity of plants.


Balsamroot seedlings from Derby Canyon Natives come in a 10 ci "cone-tainer" from Stuewe and Sons. Each of the common "cone-tainer" sizes has an associated dibble. GET ONE. The dibble makes planting in wet-soil almost easy - and certainly simplifies planting in dry soil.


For dry soil, a multiple-step operation is reasonably effective: consisting of (1) breaking the soil with a thin shovel, (2) adding water with the shovel still in place (a couple of squirts from the sprayer), (3) removing the shovel and (4) using the dibble to refine the damp hole to the correct size (usually without it collapsing, because it is now damp).


The plants will (sometimes) slide smoothly out of the cone-tainer by simply grasping the top of the plant and pulling gently. Notice I said sometimes. If this doesn't work, try using a 3/8" dowel to push through the hole in the bottom of the cone-tainer. Sometimes pushing from the bottom a couple of times and then grabbing and pulling gently from the top works. If this doesn't work (and yes, I've had occasions where NONE of these tricks work), you may have to use a packing knife to cut open the cone-tainer. If so, cut cautiously, as balsamroot roots will run close to the edge of the container and it is easier to damage them than one might think.


Planting the plants is the easiest part of the process as it is simply tucking them in the hole made by the dibble. Note however, that some of the plants will have short roots and some adjustment may need to be made on the hole. It is not a bad idea to have a small bag of conventional planting mix on hand to do quick "repairs" on the dibble-made holes.


Once planted, give the plant a couple of squirts of water. Even if dormant, the water will help "seat" the plant in the underlying soil. Once the plant is in place, center the vole-basket over the plant and hand-insert the stakes. Some of them won't go in on the first (or second or third ...) try, and you can juggle around to make things more-or-less work. (Part of planning for four stakes is that typically one is not as solid as you might like - and there is security in numbers). Then pound in the stakes with mallet.


Last (but certainly not least) check and make sure there is NO HOLE anywhere on the outside for a vole to sneak in. If there is, then either re-install the basket, or use some of the water to build a little soil "dam" around the edge of the basket to fully block the hole.


  • For a list of what to put in the truck before you set out:
  1. The plants themselves
  2. One basket for each plant
  3. Four stakes for each basket
  4. A water-dedicated backpack sprayer
  5. Extra water - about 3 gallons for every 20 or so plants
  6. The dibble
  7. A narrow shovel
  8. A small bag of planting mix
  9. A soft mallet
  10. A packing knife
  11. A 3/8" dowel about a foot long



KEY LESSONS



Some of the things we've learned: 1) Basket-integrity matters. The voles will destroy plant with an integrity violation. (One wonders how we are going to transition these OUT of the baskets, by the way ...) Our non-basket-integrity yield losses for Fall-planted balsamroot seedings are about 5%. 2) There may be a delicate trade-off between water and competing roots. For the non-basket integrity failures, virtually all of them are in locations with dense stands of either alfalfa or smooth brome. HOWEVER, some of the most successful plants are in the SAME mini-ecosystem. Saying this another way, the drier (and less competitive) locations have generally successful midsized plants - the wetter (and more competitive) locations have either really successful plants or failed plants.