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.

Wednesday, June 29, 2016

June Garden Maintenance

The annuals, dahlias, 16 containers and new 2016 perennial and woody plant acquisitions were largely planted in May. So, while I'm always on the lookout for new and rare plants June is the time to focus on maintenance. Not necessarily in any order of importance:

Prune crab espaliers shortly after flowering 
  • The 15' wide 'Sargent' crab espalier got pruned. If you don't get ornamental espaliers pruned soon after bloom next year's flowering will be diminished. The suckers on the 'Red Jewel' crab were removed at ground level. That will have to be done at least once more this summer. Tedious, but necessary.
When crab suckers spring up hack them down
  • Applications of Plant-Skydd are very effective in deterring deer. Now that the daylilies and roses are budded I spray those every two weeks- or else they'll end up in some deer's stomach. By the way, I learned the hard way earlier this month that whitetails love tropical hibiscus. I was soo-o-o-o mad when I saw that destruction. Now I've added that to the list of plants that need periodic Plant-Skydd applications.
  • The open silhouette of my Pinus glauca var.brevifolia nana (Japanese white pine) is no longer artistic by anyone's sensibility, least of all mine. The soft candles got pinched back by half to slow it down and tighten up its silhouette. Admittedly I'm coming to that party a few years late. Now it's always going to have huge open layers between years of growth. In horticulture we call that "character". Yeah, right.
Disbud tuberous begonias for massive blooms
  • The Blackmore & Langdon English tuberous begonias got moved up from their starting flats (that occurred in early April) to 8" pots. In a perfect world I've read they're supposed to be moved up in pot size several times throughout the growing season. That isn't going to happen. I always disbud the side female flowers and leave the large central male flower of begonias. Like peonies and dahlias, disbudding really expands the size of the remaining flower for those who want BIG!
Withering daff foliage ain't pretty, but leave it
  • Spring flowering bulb maintenance is partially complete. All daffs were deadheaded as soon as the flowers discolored. They were fed in spring when leaf tips emerged. Foliage is still green so it can't be cut yet. I lifted and pitched the tulips as I like to switch colors every year. I have to say I was pleased with the performance of the new Easy Bloom Pad bulbs I mentioned in last fall's 9.25.15 post. Those were a success.
  • The lawn is looking incredible with all the rain. After the first three mows at 2.5" I raised the mower to 3" for the summer and fall. That height does wonders for turf thickness, heat/drought tolerance and crabgrass prevention.
  • Roses have received their second feeding of Dr. Earth Bud & Bloom (3-9-4). They're smiley face happy.
Lungwort just 2 weeks after being cut back entirely
  • The spring blooming perennials have been deadheaded and/or cut back after spring bloom as per their needs. The plants I can think of that got cut back, not just deadheaded, were Nepeta (Catmint), Iberis (Candytuft) and Pulmonaria (Lungwort).
Watch out for poison ivy!
By SWMNPoliSciProject - Own work, CC BY 3.0,
  • In weeding, as always, I'm finding occasional little poison ivy seedlings. For that reason I'm always looking ahead since I don't weed with gloves. My observation is the poison ivy usually is under trees where birds have sat on a branch, passed the seeds and flown off leaving a potential dermatological disaster for the unsuspecting. 
  • Since I use Osmocote liberally in my containers at planting time maintenance is watering as needed, deadheading and enjoying from the chaise on the patio.
  • Beds are edged and the leaf mulch is down. Life is good in the garden!
Now's the time to sit back and savor those MOPs (moments of perfection) that we all garden for in the first place.


Friday, June 17, 2016

When Lilacs Fail... To Bloom

Judging strictly from the number of customer inquiries nothing, and I mean nothing, is as looked-forward-to in the spring garden as the arrival of lilac flowers. When the highly anticipated floral extravaganza fails to materialize, the customer's crushing disappointment is followed by plaintive questions: "What happened? What did I do wrong? Will it help if I fertilize? Isn't there something I can do?" Gardening self-doubt runs rampant.

Lose the guilt (those of you who are sure they are somehow at fault) and look at possible explanations for lilac flower failure. In my experience this is a much more common problem with what I call the "grandmother lilacs" (Syringa vulgaris - Common lilac) than the dwarf lilacs (S. meyeri and S. patula). That is, unless poorly timed pruning is an issue and then the latter may fail to bloom, too (Reason #9).


  1. You planted it in the last year or two. It was a small container grown plant. It's growing quite nicely, but there are no flowers. Plant is simply too young to set flower buds.
  2. You planted a more mature balled & burlapped plant. It's growing quite nicely, but there are no flowers. The plant is directing energy to regenerating roots left behind in the field when it was harvested. The larger the plant, the longer it will probably take to produce flowers.
  3. The plant is receiving more shade than it should. Lilacs like a minimum of 5 hours (more is better) of direct sun. Direct doesn't mean filtered through trees. If you love lilacs and want to be successful assess the site for sun before you buy. Sun, sun, more sun, please.
  4. The plant is in a bed near the lawn. The lawn is being fertilized three or more times a year with a high nitrogen fertilizer. The fertilizer is being broadcast and flung into the bed with the lilacs. Lilacs, like many plants, respond to nitrogen by producing lush stem and leaf growth. In that hormonal state lilacs are not in a flower producing mode. Upon questioning I find this happens a lot.
  5. It was an overgrown plant and someone did a hard rejuvenation pruning, cutting it back quite dramatically. It's growing back with lots of new young green stems. Same as #4. You'll have to wait for it to slow down, switch gears back to a flowering state again.
  6. The previous summer was really hot and dry. The plant didn't get supplemental water when it was under stress and chose resource conservation (read survival) rather than forming new flower buds.
  7. You had a lilac that had to be transplanted for some reason. It was a blooming size plant, but the root ball didn't hold together very well. So the shrub was, shall we say, stressed. That was two years ago and it's still not blooming. Same as #2, lilac in recovery mode.
  8. The plant flowered like a champ last year, you've never seen it so beautiful. Deadheading (removal of spent flower) wasn't done. No flowers appeared the following year. Explanation: The shrub was trying to produce seed from all of those flowers. Therefore, energy was spent in that pursuit, at the expense of this year's flowers. Deadheading might have made the difference between some bloom and none at all!
  9. In addition to all of these the biggie is pruning too late in the year. Because lilacs are spring flowering, they're blooming from buds formed the summer before. If your ______________________ (multiple choice, pick one: spouse/offspring/landscaper/gardener) pruned in July or later, flower buds that might have been forming were cut off. Bloom potential... lost. This happens a lot. Try to do any pruning or shaping ASAP after flowering is finished.

For at least nine reason lilacs can be like many Chicago sports teams, "Just wait 'til next year."    

Monday, May 30, 2016

"Swamp Dwelling" Plants

There's a creek bed running through my property that's as apt to have standing water throughout the year as it is to be dry. With the rain we've had lately the creek has jumped its bank at the lower end and flooded what I call the "delta". This, unfortunately, is not an unusual occurrence. It's a big area of soil adjacent to gardens so leaving it unplanted isn't an option.

Before going on let's underline there's a big difference between wet and periodically flooded. There are many plants that will perform and please in wet soils (defined as often saturated, but rarely with standing surface water). Floodplain sites, on the other hand, will have standing surface water for one or more days at time, multiple times per year.

I'm always entertained by customers, who upon questioning, smilingly say: "Well, water does stand in that area for more than a day at a time- but it's only a handful of times a year." That's like saying you can only drown in the bathtub if there's water in it :) It's as important for roots to get oxygen as it is for our lungs. So, always go for the worst common denominator and realize that if you have these delta-like sites you need to use flood-tolerant plants, such as:

Swamp White Oak
Swamp White Oak (Quercus bicolor) -  A majestic shade tree that eventually forms a broad spreading crown. Leaves are like green polished leather, most often with yellowish fall color. 50-60' tall at maturity. Moderate growth rate.

Baldcypress leaves, tree pictured at top
Baldcypress (Taxodium distichum) - A very defined ship mast-like central trunk that supports a very predictable conical silhouette. The foliage is citrus green and hangs on late in the fall before turning flaming rust. Interesting orange fissured trunk with age. A floodplain tree that grows really, really fast and yet has strong durable wood. 60-70' tall, 20-30' wide. Dwarf and columnar varieties exist as well.

River Birch
River Birch (Betula nigra) - One of the first plants to sulk when soil gets dry, just loves moisture. Glossy green leaves, yellow fall color. Year 'round interest with the buckskin colored peeling bark. Check out the cultivars 'Heritage' and 'Fox Valley' (a cute shrub form that gets 10-12' tall and wide).

Arctic Blue Willow
Arctic Blue Willow (Salix purpurea ' Nana') - A naturally domed shrub with fine-textured silvery blue leaves on slender stems. Grows like a son-of-a-gun when wet. It is, after all, a willow. Have seen them 7' tall and 8' wide when moist, but can be pruned frequently to contain.

Black Chokeberry
Viking Black Chokeberry (Aronia melanocarpa 'Viking') - White flowers, glossy summer leaf, striking red fall color and large black fruit that are edible! Expect 5' tall, 6' spread. It widens by suckering.

Red Sprite Winterberry
Winterbery (Ilex verticillata) - A hardy deciduous holly. Small white spring flowers are produced on both males and females. The female flowers that are pollinated produce green berries that ripen to bright red by late August/early September. The beautiful berries really stand out against the clear gold fall color. Birds gobble up the ripe berries. Consider the dwarf varieties such as 'Red Sprite' or 'Berry Poppins' that reach only 4' or so. Must have a male for every 3-5 females if you want the awesome berries. Will tolerate part shade.

Royal Fern
Ferns - Many ferns will tolerate periodic flooding and standing water. My particular favorite is Royal fern (Osmunda regalis). Perfectly happy with some sun/some shade, as well as damp (or even wetter) soil, Royal can grow into magnificent clumps 3' or more tall and wide. Clear pale gold fall color. A beauty!

The Rocket Ligularia
Ligularia - If you've ever tried Ligularia and found it lacking maybe it was sited in too much hot afternoon sun and a soil that was perhaps too well-drained. Some morning sun, for example, will enhance the varieties with colored foliage and those big leaves thrive in constantly wet sites. Check out: 'Britt-Marie Crawford', 'Desdemona' and "Bottle Rocket' to name a few for your swamp situation.

Sweet Caroline Hardy Hibiscus
Hardy Hibiscus (Hibiscus moscheutos) - The colors of these dinnerplate-sized mammoths can only be described as luscious. Brilliant red, raspberry, pink and white (often with colored center eyes) grace the summer perennial garden with their cool demeanor. Do know that Hibiscus is one of the last things to wake up from winter and show signs of life. maybe not dead, just dormant until early June.

Over the years I've tried and lost a lot of plants in the delta. The above have all survived flood "tides" with flying colors.  


Wednesday, May 11, 2016

Spring Garden Musings

If you have roses in the upper Midwest one of the first spring garden tasks is taking rose inventory. What survived, what didn't? This is one of those daunting projects undertaken with fingers crossed and a prayer in your heart that winter wasn't as horrible as you know it was. Do you get out your black suit? Are you going to a funeral? Mounding can dramatically reduce rose carnage, but doesn't guarantee 100% survival.

Grafted rose on left, own root rose on right
Courtesy Easy Elegance Roses
Rose winter hardiness has been dramatically, and favorably, impacted in the last decade with the introduction of "own root" versus "grafted" roses. At its most basic roses have been propagated for decades by grafting the desired variety (Ex: 'Peace', 'Double Delight') on the root system of a vigorous winter hardy rose, most often 'Dr. Huey', a rambling climber. The idea is to produce a larger, more vigorous plant in a shorter period of time. The downside is the golf ball-sized graft union where the canes (stems) originate is a point of weakness. Cold temperature damage to the graft and the plant may be toast in the spring. Aspiring rosarians, please heed the warning (regardless of what books may say) that grafted roses must be planted with the graft union 1-2" below the soil surface in northern climes. This is after all Chicago, not southern California.

Hardy and lovely My Girl Easy Elegance rose 
Sound the trumpets, hail the phenomenon of "own root" roses. Many roses can now efficiently be propagated by cuttings, thus surviving on their own biological roots. Upside? These roses are more innately winter hardy and won't produce 'Dr. Huey' suckers. Another difference is a two year "own root" rose will typically have fewer and smaller diameter canes than its same-age grafted counterpart. "Own root" roses can be planted at the level or a little deeper than they're growing in the pot when you purchase them.

Easy to prune clematis Etoille Violettte
Moving on, clematis pruning: The most important thing a gardener should do when buying a clematis is to record somewhere, anywhere, the name of the variety. I guarantee that in the future when you go to your local garden center to ask how to prune your clematis they will/should ask you the name of the variety. Why? There are three different classes of clematis, each with its own distinct method of pruning. Prune at the wrong time and you may be eliminating flowers for the entire growing season.

Group I: Spring flowering types that flower on buds from last year's growth. So, pruning should be minimal until after spring bloom. Any "tidy up" pruning you want to do should be accomplished within a month after bloom.

Group II: Some early through mid-season flowering varieties, that is two potential flushes of flowers.  Bloom on current season's growth from last year's stems and possibly a late summer bonus flowering from current season's growth  So, spring prune dead wood or weak stems to the plumpest, uppermost buds on whatever growth you decide to save. 

Group III: These varieties flower in summer from the growth they made in the spring. These varieties can be cut back within a foot or two of the ground late winter or early spring. Another way to put it would be to prune just above the lowest buds nearest the base of the plant.

If you're like me you'll put the name in at least two places just as insurance. There's nothing more irritating than being the party responsible for turning your clematis into a foliage plant for the year because it was pruned improperly!

Light the dark with Silveredge pachysandra
A plant you may want to know: 'Silveredge' pachysandra. Don't stop reading because you see the word pachysandra, please. 'Silveredge's' height and white flowers are identical to its green parent. The thing that makes it special is the foliage is gray-green with strong, regular cream edges. It will visibly brighten the shady areas it loves to inhabit. While perfectly winter hardy (Zone 4) it's slightly slower to fill than standard pachysandra, so space no farther apart than 6" centers, or 4 plants per square foot. Not appealing to deer- nice!

After rereading and reflecting maybe this post should have been called "mutterings" rather than musings. Just sayin'....


Sunday, April 24, 2016

Hello Spring, Hello Hellebores

As someone who has worked in garden centers for 49 years, there's precious little of a horticultural bent you could share that would shock me. Been there, heard it. Still, I admire the optimism of people that want it all.

By that, I mean the (re)quest for the elusive plant that does something splashy every season of the year. I call it the "wish-upon-a-star" plant syndrome. If such a plant existed in the upper Midwest it would:

   * bloom April thru October and be available in every color of the rainbow
   * have intoxicating fragrance
   * bear delectable, edible fruit
   * display long-lasting fall color, but
   * have evergreen foliage  
   * grow exactly the height and spread your site requires (sans pruning)
   * be repugnant to marauding deer and bunnies
   * be a way station for pollinating insects and hummingbirds
   * tolerate sun or shade, wet or dry soils

Red Racer
We plant people have all had this fantasy. But until horticultural science is more advanced and we do intergeneric gene splicing I nominate Lenten rose (Helleborus x hybridus) as a wish-upon-a-star perennial for its workhorse range of garden attributes, day in, day out.

Lenten rose is in bloom long before and after Forsythia dreams of showing its golden wares. Literally, H. x hybridus flower stems push up through snow and last year's evergreen foliage. Individual flowers can be 2-3" in diameter, one to four per stem. Because the flowers arrive in late winter Nature has given Hellebores nodding, downward-facing flowers that shed snow.

Cotton Candy
Fortunately hybridizers have been working like mad to bring the blooms to a more upright position so you don't have to lie on the ground to enjoy the wonderful range of new colors. If you're color particular like me you may want to buy named varieties so you know what color you're getting. If they're offered as generic seedlings consider buying them in bloom.

Winter Jewels Cherry Blossom
In the quest for more upright and outward-facing flowers the color range has been expanded to white, cream, butter yellow, pinks, rose, almost black and more. Many have contrasting dotting and spotting on the flowers, and they last at least 6-8 weeks. And, drum roll please, they aren't just 5 petaled (technically they're sepals), now there are numerous double-flowered series.

You want more? The flowers eventually fade and the seed pods develop an almost papery fish-scale appearance that is also long lasting. The foliage has an interesting finger-like texture and is very glossy green. Some new varieties ( H. 'Ivory Prince' and 'Pink Frost', for example) have much darker foliage with beautiful silver veins that make it an attractive foliage plant even when out of bloom. Yes, they're evergreen even in the upper Midwest. Come March "deadleafing" of winter-weary foliage is in order to make way for fresh new leaves.

Ivory Prince with winter foliage, left, then 4 weeks later
Lenten roses are tidy clump-formers, generally 15-18" tall and slightly wider at maturity. The singles may seed about, but that is easily remedied with timely deadheading. As long as they're sited in a moist, highly organic soil (a different gardeners' fantasy) alkaline soils are not a problem. Hallelujah, something that doesn't demand acidic soil! I find they're great performers in sun or shade, although they're most often recommended for partial shade sites.

Winter Jewels Berry Swirl

Hellebores are a bit like peonies in that they're happiest planted and left alone. Slug damage is occasionally reported, but I'm happy to say that's only something that I've read about, unlike many Hosta varieties. Deer and rabbits eschew (not chew, haha) Lenten rose. Is there no end to this plant's virtues? The only drawback I hear from customers is that they're slow to mature, typically taking three years to reach blooming size in a gallon pot. One more asset- winter hardy to Zone 4!

When you wish upon that perfect perennial star put Hellebore hybrids at the top of your fantasy plant wish list!


Wednesday, April 6, 2016

No Bird Brain, This Lady Part II

Hello again, friends! A vexing technical issue derailed The Hortiholic for a while but I'm finally picking up where I left off with my earlier post with Mary Francis Forde, Chalet's resident bird product buyer, discussing what you should know if you're new to bird feeding, And maybe you should read it even if you consider yourself a veteran birder.

Cole's has a range of seeds to attract, or not to attract, certain birds and critters.
Tony: Earlier we were discussing the Cole's bird seed line. I personally love it as much as you do. I get a great range of different species with their "Blue Ribbon" mix. It makes me wonder. Would you recommend a different seed blend for an urban feeder and a suburban feeder?
MF:  You might want to. If you were concerned about four-legged livestock (squirrels, mice, skunks, etc.) you don't want a mix high in fillers like millet that will end up on the ground. You might want to use safflower, which I laughingly say is the equivalent of rice cakes. It's not very attractive to squirrels, for example.

Look familiar? 
Tony: Ah yes, squirrels- the nemesis of anyone that feeds birds. Aside from the specifically designed squirrel-proof feeders (like Squirrel Buster) and the use of baffles, can you deter squirrels with smart seed choices?
MF: So, in addition to safflower you can be even more proactive. Cole's has a: "Hot Meats" blend (sunflower meats treated with liquid Habanero chili pepper and safflower oil) and "Blazing Hot" (four different seeds plus the liquid chili pepper and safflower oil). Don't feel bad for the squirrels. They will change where they dine after a bit of conditioning.

Tasteless tufted titmouse
Tony: This is the best part. What about the birds?
MF: Birds don't have a sense of taste as humans do so they're completely unaffected.

Tony: What if your feeder has been up for a while and birds aren't coming to it?
MF: You may have predators (owls, hawks) in the area which makes for nervous dining. Is your feeder out in the middle of an open area? Birds like something close by the feeder where they can land, make sure things are safe in the area, and then fly the short distance to eat. Is the feeder dirty? Is the seed fresh and dry, or is it old and rancid?

Make sure their plate is clean!
Tony: After our conversation I checked my feeder. So, even though they were eating like crazy my feeder was disgusting. Talk about dirty dishes, yuck.
MF (laughter dies down): I have to agree with you that it's not exactly a fun task, but a very necessary one. By the nature of the "residue" on a feeder washing with soap and water really isn't enough. It needs to be disinfected. Empty the feeder completely dislodging any old seed. Then immerse completely in a mixture of one part bleach to nine parts hot water. Let it soak for at least 3-4 minutes, using a long-handled brush if necessary.

Tony: Then rinse very, very thoroughly and let air dry completely before refilling.
MF: Yes. And the air dry part after many rinses is really important. Don't use a cloth where a fiber might snag and be left behind in the feeder. Why? It could absorb bleach and be toxic.
Tony: How often should this disinfecting be done, Mary Francis?
MF: Seed freshness and the possibility of disease transmission among birds are a function of how clean your feeder is. How much flight traffic do you have? How rainy and humid is it? As a general rule you should consider every 3-4 weeks.

Tony: I know people that are afraid birds won't survive if we feed them and then stop, or miss feeding for a while. Is that a valid concern?
MF: Birds are always going to take the safest, easiest food. But no, they don't become solely dependent on us to the point of not searching for food in Nature.

A source of water is so important, especially in winter
Tony: What should I have asked about winter bird feeding that I didn't?
MF: That's an interesting question. I guess people need to understand that in certain weather water is even harder to come by than food. In winter the need for water is about drinking rather than bathing. That can be provided as simply as placing a plain saucer on the ground near cover.

Tony: What about it freezing quickly when it's so bitterly cold?
MF: Birdbath de-icers or heated bird baths are the solution for that.

Tony: Mary Francis, thank you for a quick four credit course in Bird Feeding 101. Or maybe that was grad level. You're awesome.