News | Rotary Botanical Gardens

Blue Fescue (Festuca)

Posted: January 13, 2016 by Mark Dwyer in Blog

The weather continues to be chilly with my car thermometer reading a balmy 1 degree F this morning. It looks like tomorrow will be significantly warmer which will allow us back out in the gardens for lights retrieval from the Holiday Light Show (HLS). Larry H. continued processing lights this morning and has a good system for doing so. The spooling system developed by Pat M. last year has proven to be an efficient way to store many of our lights as storage space is at a premium. Alan M. was in as well and worked on some recent donations as we don’t let anything go to waste and will save as much as we can (bulbs, plugs, etc.) off a strand before it goes to recycling heaven. I bounced between seed catalogs and other tasks today. We also saw Urban and many others today.

I have always been a fan of blue fescue (Festuca) for offering color and texture. Blue in the landscape is usually understated or lacking and blue fescue should be considered for its singular and compositional value. Many years ago, the prominent ornamental blue fescue was Festuca cinerea (seen above) which has such a great shade of blue at spring emergence. However, our hot summers would frequently compromise that vivid color and create a brownish blue grass by late July that lacked the same interest provided in spring. Fescues are considered a clumping, “cool season” grass which means they actively grow and “enjoy” the cooler portions of the year and can languish in the hottest of summer months. While they prefer moist, well drained locations in full sun, blue fescue is very tolerant of drought and poor soils once established. They are also nice in containers (see bottom photo). Consider removing flowers to keep a more rounded and colorful form but it is not essential. As an “evergreen” grass, blue fescue will maintain coloration well in to winter and then will regenerate in spring (see further down). By “finger combing” them gently in late winter you can remove the brown foliage and make room for the bright new growth. Over the years, the center of the grass may die back (oldest portion of the plant) which necessitates division and relocation of the more vigorous outer portion of the plant. Recent breeding and selections have focused on increased summer heat tolerance which results in the blue coloration continuing throughout the summer. The selection Beyond Blue (‘Casca11’) seen further below is one of my new favorites for summer heat tolerance and there are some new ones coming out on the market (mostly Festuca glauca parentage). Properly sited and kept happy, blue fescue can add that touch of blue in the full sun landscape.

Beyond Blue fescue (Festuca glauca ‘Casca11’) above and two below

Festuca glauca ‘Elijah Blue’ (above and three below)

Morton Arboretum (Lisle, IL) directly above and directly below

above and below is blue fescue in April….”finger comb” out the brown (last years foliage) and let the new growth through….you wouldn’t want to shear this one back at this point as you would damage new growth which might make an appearance in the earliest days of April…

Festuca ‘Cool As Ice’ (NEW! from Intrinsic Perennial Gardens – photo as well)

Festuca ‘Festina’ (above and below) – ColorGrass Series

unknown Festuca in Vancouver, B.C.

Festuca sp. in container arrangement at Olbrich Botanical Gardens (Madison, WI)

Sweet Alyssum (Lobularia)

Posted: January 12, 2016 by Mark Dwyer in Blog

The cold weather continued this morning with a windchill around -9 degrees F. We had some fluffy snow last night and shoveled off a 1-2″ layer of the light stuff from around the Parker Education Center this morning. Big John and Larry jumped right in to processing lights from the Holiday Light Show (HLS) for storage. With a significant increase in milk jug luminaries, lights and cords this year, an “orchestrated” storage will be in order as we’ll have a lot to pack away efficiently. Alan M. came in to help the guys and was also checking over some recent donations of lights. We are no longer accepting donated lights due to a volume that we can’t keep up with efficiently and the quality of most donations isn’t consistent with what we would spend time on for repair and re-use. Janice came in to work on some volunteer-based tasks. We also saw Maury, Gary S., Dave, Cindy B. and Bill O. today. I split my time between preparations for educational events this year, catalogs and additional preparations for the Wisconsin Public Television Garden Expo (February 12, 13 and 14). We’ll again have a booth and I have quite a few presentations to prepare. See www.wigardenexpo.com/ for more information on this fun event that includes displays, vendors and lots of educational opportunities. This event has over 20,000 attendees and is great exposure for RBG.

I’m a huge fan of sweet alyssum (Lobularia maritima) which is featured in the blog today. I grew up with my mom always having a huge patch of this fragrant annual along the side of the house. I remember the patch, looking a lot like the variety ‘Snow Princess’ seen above, blooming all the way through the summer and even through some frost. My mom would then pull up the plants in mid November (with my help) and shake off the seeds in to the same bed, thereby perpetuating what would become an excellent patch each year. Native to sandy beaches and dunes in the Mediterranean region (and some other specific locations), this heat and drought tolerant annual is also called “carpet flower” for obvious reasons. Reaching a height of only 4-6″, this plant does spread and cover a good-sized area with an individual plant spreading 12-14″. Tolerant of full sun and part shade, this easy-to-grow annual can be directly sown as seed after the last frost date in spring. Also excellent for the container and basket, sweet alyssum is a blooming powerhouse and will continue to show color and interest well after most annuals have been removed due to repeated frost. While flowers will continue to appear, consider a mid-summer shearing and remove the top 1/3 of the plant followed by some fertilizer. What’s exciting to see are all the newer varieties that thoroughly explore the color range of pink, lavender, cream and even hints of yellow. Fragrance, incidentally, is mild and most notable at dusk and in the evening. Note further below the variegated form ‘Frosty Knight’ as well. Some of these selections are vegetatively produced (purchased as plants) although there are still a wide range varieties that will grow well with spring sowing. At the bottom are some photos of how this durable annual can be utilized in the garden.

Lobularia ‘Bicolor Pink Stream’ (above and below)

Lobularia ‘Lavender Stream’ (above and below)

Lobularia ‘Raspberry Stream’

Lobularia ‘Silver Stream’

Lobularia ‘Sweetness Yellow’

Lobularia ‘Yolo French Vanilla’ (above and below)

Lobularia ‘Giga White’

Lobularia ‘Snow Princess’ (above and below)

Lobularia ‘Frosty Knight’ (above and three below)

nice use as a gap filler above

great for the container (above) or basket

sweet alyssum is an excellent path edger as seen above and below

sweet alyssum will also take repeated frost (photo above from November!) and are visited by many pollinators (see below)

Serviceberry (Amelanchier)

Posted: January 11, 2016 by Mark Dwyer in Blog

The cold weather had finally descended upon us with a high temperature today around 17 degrees F. The morning was chilly enough that we were all inside the Horticulture Center working on plenty of tasks. The next couple of days will be frigid although a warm up later in the week should allow us to get back outside for more lights retrieval from the Holiday Light Show (HLS). The HLS had over 35,000 visitors this year which shatters the previous record last year of 27,000 attendees. The event isn’t over yet until the last lights are packed away…

Big John and Larry H. were processing lights this morning and had help from Marv and Alan with processing cords and more lights. Dr. Gredler was in for painting and Gene continued sanding one of our benches in need of that attention. Ron P. continued repairing lights and Maury ran errands for us. Our carpenters (Dave, Jim and Vern) had plenty of work to accomplish and Janice came in to help with some volunteer activities. We also saw Gary S. and many others today.

I’m convinced I haven’t blogged about serviceberries (Amelanchier sp.) in the past which is a shame as they are excellent in the garden. I consider them very impactful in both spring (with white flowers) and fall (with consistently excellent fall color). They also have excellent wildlife value with the summer fruits being devoured by a wide range of critters. Also called shadbush, shadblow, Juneberry, Saskatoon and other common names, serviceberries are in the Rosaceae family with 20 native species across much of North America. They cross readily so there are some hybrids that are quite exceptional with many of these “crosses” also occurring naturally. While serviceberries range in height from 6′ to well over 30′ tall in our climate, they mostly exhibit similar characteristics with grey bark, white spring flowers and excellent fall color. They are a nice small tree selection although some species fall in to the “large shrub” category. Serviceberries prefer moist but well drained soils and benefit from supplemental irrigation during a summer drought. Air circulation helps with some of the foliar diseases that might appear and the best looking specimens are those that are in conditions that mimic their native haunts (soils, pH, moisture, etc.). I have seen struggling serviceberries but usually that is a result of poor siting. Directly above is Amelanchier lamarckii which also has a great fall color. At the top and directly below is Amelanchier x grandiflora ‘Cole’s Select’ which is one of the best small tree forms. Photos further below help extol the merits of serviceberries in our garden settings. The fruits will ripen to a deep purple and become sweeter with time. Local birds will clean these off pretty quickly though so don’t delay if you want to nibble on some! The fruits rarely hit the ground as they are that coveted! Some nice fall color shots of various Amelanchier selections can be seen at the bottom.

Amelanchier x grandiflora ‘Princess Diana’ (above and two below)

Amelanchier canadensis

Pentas – Egyptian Starcluster

Posted: January 8, 2016 by Mark Dwyer in Blog

The next two days look like they will include plenty of drizzle. The temperatures might stay high enough to avoid more snow but it was damp out there today. Big John and Larry H. spent the morning processing many of the lights that had been brought in from the gardens as we dismantle the Holiday Light Show (HLS). We’ve had quite a bit of help this week with significant progress in the take down process. It looks like some very cold weather next week so the hope is that more of the remaining snow/ice layer breaks up so we can get to cords and other lights that will become even more frozen down with the dip in the mercury. Maury stopped by after running some errands and I continue to sift through a multitude of catalogs. Bill O. came in to work on some equipment as well and we also saw Dick H., Urban, Terry and a couple of others. I have some lectures tomorrow up in Amherst, WI and will travel there later today. The Portage County Master Gardeners are very cordial and I believe I’ve been involved with their winter program for the fifth or sixth time.

The blog today is a photographic tribute to a very easy to grow annual called Egyptian starcluster (Pentas lanceolata). Native to Africa, this plant would be considered a shrub or “sub-shrub” in warmer climates (getting up to 6′ tall!) but for us in the North, it is a colorful annual that thrives in the heat of our summers. In our summers, Egyptian starcluster (5 pointed flowers in a cluster) specimens will get 15″ or so and will continue to bloom until frost. While they are not too picky about soils, moist and well-drained, full sun sites with occasional fertilization are most beneficial. Egyptian star cluster varieties (mostly white, pink, rose, lavender and red) are typically purchased as plants. Consider using Pentas in summer containers as well. They are also resistant to rabbit and deer browsing which is noteworthy. Consider snipping off (deadheading) spent flowers for solid bloom coverage throughout the season. Pentas are also excellent for attracting both butterflies and hummingbirds. The variety seen above and directly below is ‘Graffiti Pink’.

Pentas ‘Graffiti Pink’

Pentas ‘Graffiti Red Velvet’ (above and below)

Pentas ‘Northern Lights Lavender’

Pentas ‘Graffiti Violet’

Pentas ‘Graffiti Rose’

Pentas ‘Graffiti Lipstick’

Pentas ‘Graffiti Lavender’

Pentas ‘Butterfly Light Lavender’

Pentas ‘Butterfly Lavender Shades’

Pentas ‘Butterfly Deep Pink’

Pentas ‘Starcluster White’

Pentas ‘Starcluster Rose’

Pentas ‘Starla Pink’

Pentas ‘Stars & Stripes’ (variegated)

Bugleweed (Ajuga)

Posted: January 7, 2016 by Mark Dwyer in Blog

Some precipitation in the form of light drizzle appeared this morning. It looks like some wet snow and sleet over the next couple of days before it gets really cold next week! The weather didn’t stop our Holiday Light Show (HLS) retrieval team of Larry H., Big John, Alan and Terry from heading out to bring in more lights from the gardens. Marv B. (later joined by Terry) continued wrapping up lights and packing them away for storage. Ron P. continued his repairs on existing and donated lights. Dr. Gredler was in for some painting and both Dick H. and Bill O. worked on some equipment including our snowblowers. Our carpenters (Ron Y., Dave, Vern and Jim) continued on their projects and Maury ran some errands. We also saw Karen M., Karen B. and many others today.

Bugleweed (Ajuga sp.) or carpet bugle, has long been popular as a vigorous, perennial groundcover. Note the term vigorous as most species of this plant do like to spread by runners and create a solid mat. The early spring flowers are typically a nice blue although pink and white are available as well. The foliage is the primary ornamental feature though. Tolerating full sun to partial shade, bugleweed will thrive in most soils but does prefer some moisture for establishment. Avoid over mulching this plant as the roots are quite close to the soil and surplus mulch can contribute to issues of rot. We don’t mulch on or around our bugleweed. Once established, this perennial is drought tolerant and will continue to spread which is the intent of any good groundcover! Be wary of planting bugleweed right against a turf edge as it will likely infiltrate and dominate the turf (consider edging!). I like the variegated forms with many represented in this blog. There are also some very dark-leaved varieties which look exceptional. Ajuga is also semi-evergreen and will retain foliage coloration well in to winter. New growth will emerge in April with blooms arriving a couple of weeks later. A healthy patch of carpet bugle will out-compete weeds successfully and is a very low maintenance option for covering up some garden real estate. Detractors of Ajuga will point out the exceptional vigor but I find that to be an asset. I don’t find it hard to dig up, relocate or limit in most situations either.