Friday, October 21, 2016

Fall Garden Punchlist

If you're a DIY gardener in the upper Midwest you can do some garden prep in early November before the real winterizing begins. It's hard to overlook the obvious, like chucking the blackened skeletons of frost-stunned annuals, emptying containers for the next color display and cutting back perennials that don't dazzle in snow. May I remind you of some more easily overlooked chores?

Hopefully, you fertilized the end of August or early September. You're no-o-o-t-t-t fi-i-i-n-i-i-sh-ed. Making another application, whether organic or synthetic, around Halloween or even early November, will give you a head start on thicker grass for 2017.

Keep mowing as long as grass is growing. Or, don't leaf (pun intended) the leaves to freeze on the lawn. Keep harvesting and removing. Leaves that freeze matted into your grass will leave an unpleasant reminder for you in the spring - a bare spot that corresponds exactly to where the leaves froze. This bare soil (in the sunny parts of your lawn) will be where crabgrass may appear next spring, as if by magic!

After planting your new spring-flowering bulbs do fertilize. Years ago we recommended putting the fertilizer in the bottom of the hole and placing the bulbs on top. Research now dictates putting the bulbs in the hole, covering them with soil and placing the fertilizer above the bulbs. Water will move the nutrients down into (but not past) the root zone.

As hardy as tulips, hyacinths and daffodils are a 1-2" layer of an organic mulch (leaf mulch, cotton bur compost, pine fines) is a great recommendation when you've finished planting and watering. We've learned that mulched bulbs produce a more uniform flower show than unmulched. Flowers may be delayed a bit since mulched soil warms slowly, but is that a big deal? Not for me either.

Bringing tropicals and houseplants back inside after a summer vacation on the patio? At least two weeks before the first expected frost do your own USDA-style inspection. Don't overlook the potential livestock biomass hiding and multiplying  even though plants appear clean at a glance.If the plant has mealybugs or mites, I would pitch it. If the plant has less difficult issues to control consider using "Systemic Granules". I recommend sequestering any summer-outside plant in a solitary confinement room (with no other clean plants to infest) for three to four weeks until you're sure it's pest-free.

Deer rubbing. Courtesy Univ. of Maryland
Male deer (bucks) are testosterone-crazed in October and November. They take their itchy-antlered frustration out on young tree trunks (less than 3" in diameter, with limbs at least 5' off the ground). These attacks can easily kill a tree by slashing off the bark. You can try a repellent (like Plant-Skydd), or put three or four heavy temporary metal fence posts in the ground a couple of feet from the trunk to deter.

Well-placed stakes keep deer at bay
Deer will eat arborvitae and yews in winter. They can be dissuaded by covering evergreens with "deer" or "bird netting". It's a black mesh so it doesn't show, but does make grazing difficult. Easier to move to the neighbors' landscape.

Rabbit damage on burning bush. Courtesy US eXtension
Bunnies maybe driven (in deep snow) to chew off arborvitae branches they can reach. They will also strip bark from burning bush, crabapples, fruit trees, Cotoneaster and hornbeam. The easiest solution is to screen the trunks with hardware cloth corrals. Remember to make them high so that with deep snow and standing on tiptoes "Bugs" can't reach over and gnaw a meal off your prized specimens. Stripped bark can be fatal. This should also offer protection from mice and voles. They're all rodents and love the same dinner fare!

Completing any, or all, of the above tasks should put a better face on your garden come spring!      


Friday, October 7, 2016

Bambi-Proof Bulbs

It's fall and a gardener's fancy turns to thoughts of a stunning spring garden radiating color from bulbs. Increasingly many of us have to garden with one eye on that prize and the other on lookout for the next raid from White-tailed deer. If Odocoileus virginianus regularly plunders your garden consider the following spring-flowering bulbs whose flavors are decidedly unpalatable to Bambi.

Allium (Ornamental onion) - Their popularity continues to explode exponentially, as it should. Check out the diversity of flower sizes, colors, bloom times and ease of maintenance that makes one or more of the varieties suitable for almost any imaginable garden situation (except deep shade). Loved by pollinators, Alliums are hated by deer and rabbits for their strong odor and bitter taste when cells are crushed. Don't worry, it won't even get to the taste test.

Camassia (Camass or Quamash) - It's hard to find tall spring-flowering bulbs and Camass does that very nicely, thank you. Grows to 20" and blooms at the end of spring bulb time. Prefers a bit more moisture than most spring bulbs and full sun, but tolerates light shade. Deer and rodents will take a pass.

Galanthus (Snowdrops) - I saw these in a mass planting early this spring and thought, "Why haven't I grown these?" These little charmers bloom right through snow. The downward-hanging, milk-white flowers with green tips remind me of airplane propellers. Subtle, so plant in groups of a dozen or so. They'll naturalize since they're animal-proof. I want to plant the double-flowered Galanthus (flore pleno) this fall. 6" tall, partial sun.

Leucojum (Snowflake) - Late spring blooming, pendulous, bell-shaped white flowers with green dotting on the tips. Long-lasting flowers, elongated, strappy foliage. Part sun/part shade and moist sites. Depending upon species, may get 12-20" tall. Neither deer nor rodent, nary a nibble!

Muscari (Grape hyacinths) - The search for "different" has brought many new forms of this old favorite to our gardens. The standard M. armeniacum is a beautiful cobalt blue naturalizer that doesn't flinch in the face of a deer onslaught. Muscari are different than most bulbs. How so? They produce a few inches of grassy foliage in early fall that remains in place, evergreen, over the winter. Some cunning gardeners use Grape hyacinths to mark areas where larger, major bulbs are- by planting Muscari around the perimeter. This leafy halo helps highlight where the other bulbs are resting during fall and early spring. This can prevent shovel damage if your garden memory gets hazy over the winter. Mine sometimes does, unfortunately....

Scilla (Squill) - The charming blue "haze" in many peoples' spring lawns is almost always from naturalized Scilla siberica. 4-6" tall, grassy foliage blends right into the grass. Reproduces freely by seed and bulbs. Partial shade or full spring sun are fine. Deer and rodents won't stop to dine on this plant.

Daffodils - Deer, rabbits, rodents.No animal is interested in any part, whether it's the bulb, the leaves or the flowers. Totally off limits. Plant daffodils and know that your spring garden will be untouched. 

If none of these suggestions send your horticultural pulse racing (this is by no means a complete listing of all deer-resistant bulbs) and you must have the wonder of tulips I hear you and feel that need, too. So:

  • Check out the small species tulips. They are smaller in stature and flower size, but some do exhibit deer resistance.Otherwise,
  • Be prepared to spray standard tulips with repellents when they emerge, when buds are first visible down in the leaves, and just before buds show color. If you'd like a recommendation, I've had great luck (and beautiful tulips) using Plant-Skydd.

Bulbs, buds, blooms. Just beautiful.  

Saturday, September 17, 2016

A Perennial Divided.... Fall or Spring?

Much has been written about dividing perennials. There are many reasons for unceremoniously removing a perennial from the comfort of Earth, separating into smaller plants and replanting. Why do this at all?
  • Increase stock of a favorite variety (for your garden or to give away)
  • Keep plant size in the bounds of its dedicated space in the garden
  • Improve the vigor of an old plant (especially perennials that "die out" in the center)
  • Improve flower quality and quantity with a new, young plant
  • Relocate to a new site
Experienced gardeners often say, "Divide spring-blooming perennials in the fall, and fall-bloomers in spring." There's a certain amount of truth in that. But, like everything we do in the garden there's often a fudge factor if something has to be moved. Here are some garden stalwarts that favor fall division.
Buckeye Belle
Peonies - There's little leeway about the time of year to divide these May stunners. Late summer - early fall is the only safe season to divide a peony. If properly sited in a well-drained, sunny site they're a perennial that just gets bigger and better with each passing year. Frequent division is NOT recommended.

Mid-August through late October is the best peony transplant time in northern Illinois. At this time the pink, red or cream "eyes" (next year's stems) will be fully formed and visible at the base of this year's stems. Cutting to 3-5 eye divisions is a standard recommendation. It will take a year or two to recover from transplant. (9.11.15 Hortiholic post "Prime Time for Peonies" has more detailed info on the planting process).

Chicago Apache
Daylilies are much more forgiving of transplant season than peonies. I personally prefer dividing in September. I read a recommendation in a daylily catalog years ago to transplant when a plant reached 20 fans (a stem of connected leaves) of foliage. That's a hefty daylily. Daylily roots are fleshy and tend to separate fairly easily without lots of mechanical cutting. While you could divide and replant as little as a single fan it's going to be a while before that produces an impressive flower show. I find a 3 fan division produces a good display the next summer.

Princess Victoria Louise
Oriental poppies, when established, make a gorgeous plant with their deep green foliage and splashy crepe paper-like flowers. It's important to know that a month or so after they bloom the leaves start yellowing and the plant disappears, going dormant for weeks in the summer. When a poppy has done its Rip Van Winkle slumber thing it will suddenly (mid-late August) throw up a little rosette of leaves 6" or so tall. These must not be cut off. Those leaves will remain over winter and flower next spring. "Orientals" have a taproot so any type of transplanting or dividing should be kept to a minimum.
Picasso Moon
Bearded iris are probably best separated every four years. They can be lifted and divided as early as 6 weeks after they finish flowering. That is well before fall. The earlier in the summer you do the division the more likely it is that you'll have flowers the next spring. Two cautions: Cut and keep only the newest rhizomes (the creeping rootstock) on the outer edge of the clump, the ones that haven't flowered. Replant those, discard the old, woody ones. Once a rhizome has flowered it will never flower again. Also, make sure the top of the rhizome is replanted slightly above the soil surface. It's a no-no to completely cover bearded iris rhizomes with soil.

Gold Standard
Hostas ... forget the rules. They have. You can lift and separate them spring, summer and fall. I like fall. In mid-late September I cut off the foliage, lift the clump and start dividing. I have an old kitchen knife (long and heavy) that I use to saw through old clumps. Like peonies I leave 3-5 "eyes" per division to give a good show the following year.

Go forth, be fruitful and divide those perennials (but only if they need it)!       



Thursday, September 1, 2016

Literal Dos & Donts of Fall Lawn Care

  • DO know that August 15 to September 15 is the very best time to do lawn repair in northern Illinois, whether seeding totally bare areas or overseeding thin lawns. Yep, actually better than spring due to less weed competition.
How much sun? This will help
  • DO due diligence and figure out how many hours of sun, partial sun/shade or full shade the area gets. Your ultimate success (or failure) depends upon getting an accurate estimation BEFORE you buy the seed.
  • DO measure the area to be seeded so you know how much seed to buy. Overseeding requires half the rate of totally bare soil.
  • DO assess whether you're going to overseed (recommended if you have 50% or more desirable grass) or kill everything and start from ground zero.
  • DON'T use a broadleaf weed (dandelion, clover, etc.) control to kill weeds before seeding. There's a lengthy restricted time between using these products and being able to safely reseed.
  • DO consider using "Roundup" if you need to knock out everything for a start-from-scratch new lawn. "Roundup" is a nonselective herbicide, absorbed only through green, growing leaves and allows you to reseed almost immediately.
Start with the good stuff
  • DO buy the best seed. It may be a couple of dollars more a lb. but it won't have the inert junk or crap and weed seeds you'll get with "value" seed.
  • DO use Kentucky bluegrass for lawns receiving 5 or more hours of sun a day. Use fescues when you have, say, less than 4 hours of direct sun a day.
  • DO a mixture of KY blues and fescues if you have sun and shade. Don't worry, Darwinism will intervene. In the sunny areas the blues will dominate and in shade fescues will prevail.
  • DO check out having core aeration done if your thatch layer (the spongy layer at the junction of roots and stems) is more than 1/2" deep. 
  • DON'T dethatch. Dethatching is not a sound horticultural practice. Don't do it or have it done. There, I'm climbing off my soapbox.        
  • DO consider slit-seeding if you have a large (bare or partially "grassed") area to renew. Briefly, it's a machine that cuts parallel furrows in to the soil, drops the seed uniformly in those grooves and gives a great result.
  • DO know a slit-seeder is a little like trying to push an elephant around the yard. They're heavy. So, if you're a DIY person they can be rented. Or you can have reputable landscape firms do it for you.
  • DO loosen the soil, preferably to a depth of 3-4". This will promote deep rooting. Harder to do if you're overseeding into an existing lawn. That's when slit-seeders are a smart choice.
  • DO apply the seed at the appropriate rate. Nothing is gained by applying seed too heavily. You should be able to see individual seeds on the soil. They should be close, but not clumped together or on top of each other.
  • DON'T cover with peat moss. Never, ever. If you feel you need to cover the seed a light (and I mean light) dusting of topsoil or fine humus is acceptable.
  • DO use a starter fertilizer. Many lawn fertilizers contain no phosphorous, which is fine for established turf. Starter fertilizers do have phosphorous (the middle number in an analysis, 25-24-4, for example). Seed, or sod too, will really respond to high phosphorous with a heavy root system!
  • DO moisten the seeded soil surface frequently to keep uniformly damp to ensure good germination and establishment. 
  • DON'T flood the seed so that it's floating about.
  • DO the first mowing (with a sharp blade) when the surface is about 3" tall.                 

Friday, August 19, 2016

2017 Flower Fashion Forecast

Whether it's fashion, interior design or gardens, colors change dramatically from one season to the next . That's one of the things that makes gardening so creative and so much fun. There's always something new to try.

I recently had the privilege of attending "Cultivate" (an industry show in Columbus, Ohio) and visiting Ball Field Day (West Chicago, Il.). These are top venues to see what's new and trending in annuals. Here are some of the plant fashions that caught my eye.

Petunia and Callibrachoa ("callies") breeding continues to give us new forms, sizes and colors. Perfect example - PanAmerican's Sophistica Lime Green is just an extraordinary color! If Hydrangea paniculata 'Little Lime' sales are any indicator of lime's popularity then many people will be swooning over this gorgeous petunia of similar coloration.

Instant combinations simplify creating stunning containers and hanging baskets. Hundreds of combinations have been pre-designed for you. For example, "callies" of different colors OR different annuals of the same, but harmonious, color families are pre-planted together. You buy the combos in 6" (or larger) pots early in the season and "drop" them into your decorative container. Voila! If you consider yourself to be color-challenged a designer look is finger snapping easy with "instant combos".

Angelonia (Summer Snapdragon) has been at the top of my favorite annuals list for a long time. I love its: heat tolerance, height, range of wonderful colors and, of course, the flower longevity. Each bloom spike literally lasts for weeks. There are many different series out there, but I was knocked out by BallFloraPlant's Archangel Cherry Red. Killer.

Canna is a plant I remember from my grandfather's garden. Well, cannas are ba-a-a-c-c-c-k and better than ever. They're easy, forgiving of neglect, although they really show off when kept moist. Cannas make a bold statement with their huge leaves (green or bronze options) and big sassy flowers. They endear themselves to novice and veteran gardeners alike by flourishing in the most intense heat. Now, instead of planting big tubers there are new series being grown from seed which means you get knockout effect with easy planting of 4" or 6" pots. Cool!

Begonia diversity is astonishing. With Impatiens Downy Mildew still a raging reality any annual with shade tolerance (or preference) is in big demand. So, hybridizers have been busybusybusy creating begonias with results that we can all enjoy in our gardens.

Celosia (Cockscomb), especially the crested varieties, intrigue me to death. Their convoluted texture always reminds me of velvet brains. I dare you to grow them and not ever touch them. Impossible. They're way too irresistible in a tactile way. Check out the designer varieties above.

Coleus, coleus everywhere at both venues. While they thrive in partial shade breeders are succeeding with more sun tolerance. Versatile in pots or beds there's a coleus for everyone now. Coleus are for foliage so just keep those flower buds pinched off before they open and drop little blue flowers around!

Vinca (aka Flowering Vinca or Periwinkle) can be confusing. There's the annual vinca vine, hardy evergreen ground cover Vinca minor and annual flowering vinca. If you have hot sites that sometimes don't get watered as often as they should annual vinca should be a prime consideration. That's Catharanthus roseus if you're Googling already. They mound nicely and shed their spent flowers so there is virtually no maintenance. The secret is not to rush spring. Plant them in late May when you feel safe to put tomato plants out. Again, hybridizers have done wonderful things including both larger and smaller-flowered varieties.

Be a garden fashionista next spring and try what's new. Family and friends will definitely notice your new garden look. Honest, they will.


Saturday, July 30, 2016

Know the Enemy... Japanese Beetle

Summer is here, the heat is on. One of our least desirable imports, Japanese beetle, is foraging in gardens and laying eggs that will hatch 10-14 days later as root-feeding grubs. I'd like to share some of the collective wisdom I've heard over the years. These facts may help you refine your plan of attack and minimize damage.

While "first emerging" adult JBs clamber out of the ground early July (in Chicago) it can be mid-August before they have all materialized. This means at least 6 weeks or more of potential adult feeding damage. Not good news.

Voracious activity on grape
What do adult JB adults like to eat? Unfortunately, they will consume from a palette of more than 300 plant species. At the top of the preferred menu:

  • Trees such as linden, birch, Japanese maple (logically enough), crabapple, Norway maple
  • Roses
  • Climbing Hydrangea (from personal experience)
  • Hardy Hibiscus
  • Hollyhock
  • Raspberry and blackberry

Adults fly to the top of preferred host plants growing in sun to feed. If undisturbed they tend to feed on the same plant for 3 days at a time. At that point some signal causes them to move on, flying up to 1/2 mile to a new host plant. Consider this fact when thinking about putting up a JB trap (with their 2 scent lures). Consensus is traps attract larger numbers to your garden, with only a percentage meeting their maker in the trap bag.

Adult JBs have a quirky habit late in the afternoon and evening. When disturbed at that time they fold their legs and drop straight down from their feeding perch. Earlier in the day they will tend to fly up, up and away. If you have the time and patience there's an easy way to capitalize on this PM drop-and-roll behavior. Put soapy water in a wide mouthed jar. Place it under the feeding beetles(s), tap and they should drop right into the jar. Boom, done. Consider you may have to do that a lot of times...

Interestingly, they are attracted to plants that are/or have already been fed upon by other JBs. Taste-tested leaves evidently emit a tantalizing odor that serves as an attractant. In addition, satisfied early feeders emit a hormone that also serves as a **** review drawing in additional diners. If you feel control in any form is warranted consider knocking down (your choice, physically or chemically) the first adults so they don't leave their calling card. This should mean less feeding damage for the season.

When feeding and mating are accomplished females scout for sunny areas with good soil surface moisture to deposit their eggs. This is generally done around dusk. So, yes there's a reason that in years with high JB populations and low July-August rainfall heavily irrigated lawns are more apt to have grub infestations than unwatered grass. If your lawn has historically had JB issues you might consider irrigating less frequently, but more deeply, during the mid-July through mid-August egg laying period. Let the surface dry out. I personally like the idea of my lawn having to develop a deeper root system while seeking water.

Eggs hatch in ten to fourteen days (depending upon soil moisture and temperature). Grubs start feeding on the roots of grass and other plants, but especially the former. Grubs can affect turf turf health and vigor by feeding on roots. There is general agreement that control should be considered when grub populations reach a 10-12 per square foot threshold.

Japanese beetles, game on!

Friday, July 15, 2016

June at Olbrich Botanical Gardens

As spring slides into summer it's fun to get out and visit garden centers (you never know when you'll score a new plant for your collection) and botanic gardens. Of the latter, one of my favorites is Olbrich Botanical Gardens, Madison, Wisconsin. At 16 acres it's an intimate showcase for lots of different garden styles that flow naturally from one to another. I try and visit every year and am always glad that I made the drive.

"Prairie" done well greets you at entrance

This durable dogwood has it all
Corneliancherry dogwood (Cornus mas) This is a tree that should be used more often. Great seasonal interest with: early and long-lasting yellow spring flowers, great dark green summer foliage, red late summer berries, burnished purple fall color and checkered buckskin bark on larger trunks. This is a great alternative to standard evergreen screening. Will do in sun or shade, can be grown as a single trunk tree or clump form (as shown).

A groundling clematis!
Clematis xdurandii  Who'd have thunk it? Clematis aren't just for trellises. Some of  the integrifolia clematis are well suited for clambering over the ground and through other perennials. What a great way to cover old tree trunks or cascading over a low wall. And a long, long season of bloom. You may more readily find Clematis integrifolia than C.  xdurandii, but you never know.

Gorgeous gams of paperbark maple
Paperbark maple (Acer griseum) This is at the top of my ten favorite plants, be it tree, shrub or perennial. This ornamental maple has beautiful dark green trifoliate summer leaves, spectacular scarlet red/orange fall color and this amazing 365 days-a-year peeling mahogany bark. Smashing!

Tall and lovely meadow rue
Meadow rue (Thalictrum rochebrunianum) There's something cool about an airy perennial that gets 6' tall.

Something different for your containers?
Porcupine tomato (Solanum pyracanthum) - This is a plant I'd heard about, seen in pictures, but never experienced in person. Cool orange spines with marble-sized, greenish-yellow fruit. NOT edible, but could be an interesting specimen (grows to 5' tall) in a stylized contemporary container.

Illuminating pachysandra
'Silver Edge' Pachysandra (Pachysandra terminalis 'Variegata') I will continue to carp about how much I personally love this plant for what it does in a deep shade area. What does it do, you ask? It lights it up in a beautiful, subtle way. End of harangue.

Succulent scene
Olbrich displaying the diverse range of succulents and giving them their due as a fantastically popular, low/no maintenance family of plants.

Firelight panicle hydrangea sizzles now and later
'Firelight' Hydrangea (Hydrangea paniculata 'Firelight') This quickly soared to the top of my Hydrangea popularity list last year. Had to have these fresh, long-lasting white flowers that age to smoky raspberry pink, 6' tall and wide.The panicle Hydrangeas really want at least 1/2 day of full sun and more is even better. As Hydrangeas go the "panicle" varieties are fairly drought resistant.

Climbing hydrangea showing off as usual
Climbing Hydrangea (Hydrangea anomala subsp. petiolaris) This is a handsome, handsome vine. It's adhering so best grown on a rough, solid surface. Will do in sun, part or full shade. Develops lacy white flowers in early summer on the horizontal "arms" it produces with age (this one is just starting to bud). Handsome peeling cinnamon-colored bark on larger diameter stems makes for great winter interest.

I believe you learn something from every garden you visit. Hopefully, it's something positive, but sometimes it's as simple as what not to do. A visit to Olbrich Botanical Gardens is always a lesson in how to do a garden right and what plants to use to accomplish a beautiful end result.