Ask the Master Gardener: Get the lead (plant) out and into your garden

Dear Master Gardener : A friend who is a native plant enthusiast has Lead Plant. Is that a good addition to a perennial garden? I am trying to add more native plants to our landscape. Answer : Lead plant (Amorpha canescens) got its name because it was common above the lead mines of the Driftless Area, an area that encompasses parts of southeastern Minnesota, southwestern Wisconsin, northwestern Illinois, and northeastern Iowa, and never glaciated.

It is native to most of Minnesota, except for the northeastern region. Technically lead plant is a shrub, but never gets larger than 3 feet, so it can act as a tall 30-inch perennial. It is a good addition to your garden, as the foliage and flower spikes add visual interest.



The leaves are covered in fine white hairs which give them a woolly grayish appearance. The flowers are up-facing, multi-branched spikes that are a dark indigo color with contrasting yellow-orange stamens. They bloom from the bottom of the spike up.

The flowers produce little legume pod fruits that decorate the plant into winter. Grow lead plant in full sun with well-draining soil. Once it is established, it is long-lived, and heat and drought tolerant.

ADVERTISEMENT Dear Master Gardener : I went to the store to purchase grass seed, but there are so many from which to choose. What should I look for in a grass seed mix? Answer : Before shopping for seed, know which turfgrass species and characteristics you want for your lawn. Seed mixes can contain more than grass seed, so check the seed label on the bags because they include important information about the quality of seed.

The following information comes from Noah Burley and Eric Watkins, turfgrass science professors at the University of Minnesota. Minnesota turf species include fine fescues, of which there are five (strong creeping red, slender creeping red, hard, Chewings, and sheep), Kentucky bluegrass, and perennial ryegrass. Fine fescues are often mixed with Kentucky bluegrass.

The advantages to fine fescues are they are drought, shade and salt tolerant; however, they do not do well in extreme heat. Strong creeping red and Chewings fescue are the most tolerant of tree shade. Kentucky bluegrass usually does not grow well in shade.

It is higher maintenance than most other cool season turfgrasses, as it requires more frequent mowing, fertilizer, and water. With that said, it is the most popular turfgrass in Minnesota and most widely available species as sod. It is often used on home lawns, parks, golf courses and athletic fields.

Perennial ryegrass lacks winter hardiness, has higher maintenance requirements, is susceptible to many diseases and often produces unsightly stems in late spring. It does have good wear tolerance and is quick to establish. Some perennial ryegrass seed is produced in northern Minnesota.

Some options for ultra-low maintenance include Prairie Junegrass, Tufted Hairgrass and Buffalograss. Options for dense shade include Supina Bluegrass and Rough Bluegrass. They need areas with plentiful moisture and the seed is expensive.

Keep these factors in mind when shopping for grass seed: match your grass species to the amount of light, moisture and soil type of your lawn. Make sure you are paying for grass seed, as bags of grass seed often contain inert material, weed seeds, seeds that won’t germinate and other crop seeds. Single variety bags may be easier to install but can increase maintenance over time due to their susceptibility to disease and pest damage.

Seed blends combine several varieties of the same grass species, whereas seed mixtures contain more than one species. A mixture of multiple species is generally the best for most home lawns. When it comes to grass seed you get what you pay for.

Seed values tend to directly correlate with their price. Seeds with low prices tend to result in poor quality lawns, whereas high-priced seeds usually result in high-quality lawns. Avoid poor grass choices that are often added to mixtures due to their low cost: VNS or variety not stated, Linn perennial ryegrass, Nui perennial ryegrass, annual ryegrass, Italian ryegrass, and common creeper.

When looking at the labels on grass seed mixes look for purity greater than 90%, germination rate greater than 85%, a test date within the last nine months, less than 0.5% other crop, less than 0.3% weed seed, less than 8% inert matter and no noxious weeds.

Dear Master Gardener : Is spring the best time to prune trees? ADVERTISEMENT Answer : Pruning at the correct time is important for the health of your trees. Pruning during the late dormant season (late winter, before spring growth begins) is best for most trees. Oaks should be pruned by now — they should not be pruned in April, May, or June due to the potential for oak wilt infection.

Apple trees, including crabapples, should be pruned any time between February and early April because spring or summer pruning will increase the chance for infections and/or the spread of fire blight. Trees that have free-flowing sap, such as maples, butternut, walnut, birch, ironwood, and blue beech can be pruned when their leaves are fully expanded in late spring or early summer to prevent bleeding. Remember not to remove more than one-fourth of the live foliage.

Although there are a few exceptions, evergreens need little pruning. Different types of evergreens should be pruned according to their varied growth habits. Spruces and firs do not grow continuously but can be pruned any time because they have lateral (side) buds that will sprout if the terminal (tip) buds are removed.

It's probably best to prune them in late winter, before growth begins. Some spring pruning, however, is not harmful. Pines only put out a single flush of tip growth each spring and then stop growing.

Prune before these "candles" of new needles become mature. Pines do not have lateral buds, so removing terminal buds will take away new growing points for that branch. Eventually, this will leave dead stubs.

Pines seldom need pruning, but if you want to promote more dense growth, remove up to two-thirds of the length of newly expanded candles. Don't prune further back than the current year's growth. Arborvitae, junipers, yews and hemlocks grow continuously throughout the growing season.

They can be pruned any time through the middle of summer. Even though these plants will tolerate heavy shearing, their natural form is usually most desirable, so prune only to correct growth defects. Arborvitae won’t grow back from pruning behind the green growth.

You may get your garden questions answered by calling the new Master Gardener Help Line at 218-824-1068 and leaving a message. A Master Gardener will return your call. Or, emailing me at umnmastergardener@gmail.

com and I will answer you in the column if space allows. ADVERTISEMENT University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. Information given in this column is based on university research.

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