Biennials’ unusual life cycles can challenge some gardeners

Q: I am a frequent reader of your column and a sporadic gardener. I can usually get along OK with annuals and perennials but I am slightly stumped by biennials. I purchased some beautiful hollyhocks at a yard sale a few years ago and put them in. They grew and were lovely, but the next year I didn’t see them and thought that they had died. The next year they came up and the following year they did not.

However, this year they came up and spread. I love them, but how can I outwit them so I can have some every year? – Jeri, e-mail

A: The life cycle of a biennial is a little more complicated than that of an annual or perennial. Technically, the term indicates a plant that grows vegetative matter in the first year from seed and flowers the next. That said, some plants, such as certain cultivars of hollyhocks, may be biennials or short-lived perennials.

In most decent garden soils, hollyhocks self-sow very easily. Each flower on those tall stalks you see in late summer produces several dozen seed. Once ripened, the seed falls to the ground and may lie dormant in the soil for some period of time (a number of years) and still maintain viability, so this season you may have been seeing offspring of the original plants.

In late summer, to help ensure a crop of flowers every year, collect, dry and freeze in an airtight container seed from your hollyhocks. They are easy to start inside on the windowsill in early April or you may start simply by broadcasting them across your garden bed each spring.

Q: Last year, we were told that a particular seafood compost was the very best for all of our growing needs. A large amount was purchased and much to our dismay not even lowly weeds will grow in this mixture this year. We are using loam with a small amount mixed in with limited success. Do you have a solution?

I have another problem. I am attempting to create a new flower bed out of an area of lawn that has probably only grown grass in the past 125 years.

The soil is like sponge (similar to peat moss). The Rototiller jumps up and down when I try to dig. What should I do? – A.A., Milbridge

A: To address your first concern: Without knowing what particular brand compost you purchased, I can only make a general comment. Typically bagged compost (perhaps you purchased yours unbagged in bulk?) shows at least some of the chemical and physical properties of the product. This information is useful in deciding how to use it in amending soil.

Perhaps the supplier – particularly if the product was obtained in bulk – didn’t properly compost the material. If it was ill-fragranced, this could be an indication that the composting process was incomplete – resulting in a high nitrogen content that could “burn” and-or thwart plant growth.

I would suggest having a sample tested by the University of Maine analytical lab (through your local Cooperative Extension office). This will cost you a small fee but will provide some scientific analysis of the product.

As for your second concern: the spongy area sounds like an ideal candidate for what’s called “double digging.” This procedure is a lot of work, but well worth the effort if you want a high-quality soil in your flower bed.

Unfortunately, this is a manual labor job, not a mechanized one, unless you want to hire a backhoe (which might be warranted, if the job is large enough.)

Come spring, here’s what to do: define the area of your garden bed using string and stakes or by spray painting an outline of the bed on the ground.

Begin the double-digging process by excavating the soil in that defined area to a depth of about 1 foot. This soil is placed aside and the next foot or so of the soil profile is removed. The first foot of soil to be removed is than placed at the bottom of the trench that has been dug and the bottom foot of soil removed is then placed on top. Essentially, one is digging deeply and replacing the topsoil with the soil from the lower portion of the soil profile. The new, fresh – hopefully nonspongy soil – should then be amended with organic matter and perhaps lime.

Again, it would be wise to sample and test the soil using the services provided by UMaine. The test results will be very helpful in directing you to create a healthy garden soil.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, 512 North Ridge Road, Montville 04941 or e-mail dianagc@midcoast.com. Selected questions will be answered in future columns. Include name, address and telephone number.