Hey there! It is your hip, non-hipsta’ horticulturalist back at you, sipping my coffee and applying my horticultural brain toward the questions my vast fan base asks of me. This week, I shall tackle the oft’ asked questions concerning the late season planting of various categories of plants:
- When should I plant tulip bulbs?
- Can I still divide and transplant this perennial?
- How late can I plant trees or anything else?
First, the tulip bulb controversy. I say “controversy” because some people get themselves all worked up about timing. The generally accepted wisdom says to plant tulips 6 to 8 weeks prior to first frost, or more accurately: when soil temperatures drop consistently below sixty degrees, which for this part of Elkhart means roughly September to October. Personally, I think this is a cart of animal fertilizer; here is why. Tulips, like other spring bulbs, require a chilling period to break dormancy. They were designed with this mechanism to prevent premature, out of season growth. Tulips require, on average, twelve to fourteen weeks of moist soil temperatures below forty degrees. Name me a year where late spring and summer soil temperatures dip that low for that long of a time…still waiting…go ahead and Google it. The real answer, in my opinion, is you can plant a tulip bulb any time. It just happens to be a lot easier to plant your tulip patch on cleared land.
Next, the question regarding herbaceous perennials, shrubs and trees. This is another overly thought out topic. In gardening, like in the rest of life, there is the ideal and then there is, “Oh man I forgot to do that five weeks ago. Am I out of luck for this year?” I tell people, start by answering your gardening question with a little science – a little biology, really – for the “ideal” is based on what is happening biologically. Standard advice says to get your newly acquired or divided herbaceous perennials in the ground one month or so prior to the ground freezing, or immediately after flowering (unless it is a late fall bloomer like asters and mums). That is the ideal since it provides ample time for roots to establish and store up some energy against the rigors of winter. Again, I think that is somewhat a cart load of smelly stuff. If you are panicked, do not be. Fear not, my dirty handed friend. When dealing with conditions outside the “ideal”, one just has to take extra measures and accept some risk of failure. Your perennial just might not make it regardless of what I tell you here. Sorry.
Having said that, there are some precautions you can take to increase your chances of seeing beautiful leaves unfurl when spring air arrives.
- If dividing, and really this is true anytime, make sure you get as much root system as possible. This is the plant’s starch cellar, storing up energy for the spring push.
- Be sure the newly placed plant is watered regularly, even if leaves at the top die back. Roots are still alive and growing down there so, feed Seymour what it wants.
- Mulch around the root zone with a nice thick layer of leaves or wood chips. This will allow a slightly longer warm period for root growth, and it also buffers the extremes winter brings to those baby roots.
- If planting a large tree, you may need to stake it through the winter to prevent the root ball rocking right out of the ground if it lacked an opportunity to establish.
How do I know this can be done? Because I have healed in hundreds of perennials and large woody plants over the years, ABOVE ground with wood chips and they go on to be stars in their fields. Sticking the plant in the ground late, even after the ground is frozen, is no different from sticking a pot under a very thick layer of organic matter. In a way, it is actually a better way to temporarily overwinter plant stock.
Hope these tips have eased your mind and given you a chance to warm up whilst reading. Happy planting!
Josh Steffen, Horticulture and Facilities Manager