Sunday, March 31, 2019

Houstonia, We Have ... Tiny Flowers


Living in the same area for many years means that I see some of the same plants over and over. It’s kind of nice, like seeing old friends. Sometimes, plants that you’ve still seen many times still have the power to impress you more than usual. Bluets (Houstonia spp.) have been that way for me lately.

Of the 8 species of Houstonia found in Georgia, there are spring-blooming ones and summer-blooming ones. Right now, the spring ones are winking up at us from very low on the ground. You probably won’t be surprised to know that these small plants in the madder family (Rubiaceae) have some small native relatives like buttonweed (Diodia), bedstraw (Galium) and partridgeberry (Mitchella). You’d be more surprised to know that buttonbush (Cephalanthus)  and Pinckneya are also in that family!

Houstonia pusilla
Two species of Houstonia are blooming now in my area. The annual tiny bluet is Houstonia pusilla. I can see it in my neighbor’s Bermuda lawn and all along roadsides with closely cropped vegetation, conditions that allow its seeds the bright light and lack of competition that they need to flourish.  It is most often blue but sometimes it is white. The plant blooming now comes from a tiny rosette that formed over the winter. I am still trying to convince it to live in my yard. In the meantime, I admire it from afar. Notice that this species has a reddish-purple center.

The second species is a perennial one: Houstonia caerulea also has a small rosette of tiny leaves. It usually grows a bit taller than the annual species but still not more than 6 inches. Common names include azure bluet and Quaker Ladies. I usually find this one in moist, mossy areas such as a damp ravine. I’m still trying to get this one going in my yard as well. I think it was eaten last year by a more aggressive neighbor. Notice that this species has a yellow center; it shares this characteristic with thymeleaf bluet, Houstonia serpyllifolia, which grows in the mountains, as well as with the Southern annual bluet, Houstonia micrantha.

Houstonia caerulea

A uniquely Coastal Plain species is the round-leaved bluet, Houstonia procumbens. Tiny flowers sprout from creeping foliage in the spring, and the bright whiteness of the flowers evokes another one of its common names: innocence. I saw it on the side of a road in the Okefenokee Swamp during a trip with the Georgia Botanical Society.


Houstonia procumbens

Houstonia longifolia

The remaining 3 species are summer bloomers.  Houstonia canadensis is found in North Georgia and recognized by the presence of basal leaves at flowering time compared to the others in summer. Houstonia longifolia and Houstonia purpurea are similar and more widespread, except for the shape of the leaves. I believe what I found once (and I’m not even sure where) is the long-leaved bluet.

Now that you know these little guys, keep an eye out for them. They are sweet little members of our native plant communities.

Sunday, March 24, 2019

Your Relatives Drive Me Crazy


Cardamine angustata
Slender toothwort (Cardamine angustata, formerly Dentaria heterophylla) is a favorite spring perennial of mine. It first appears in late December when its low foliage braves the winter cold, long before any other ephemeral shows a single sign of life. It won’t bloom until mid-March, after the trout lily (Erythronium umbilicatum) and bloodroot (Sanguinaria canadensis) have won us over with their charms.

Several other species of toothwort have found their way into my garden: cutleaf toothwort (Cardamine concatenata), crinkleroot (Cardamine diphylla), and dissected toothwort (Cardamine dissecta) are all just as lovely, gifts from plant friends over the years. A cousin of theirs, bulbous bittercress (Cardamine bulbosa) came from another friend, transplanted from Greene County, GA.

It is another relative of the toothworts that drives me crazy this time of year: hairy bittercress (Cardamine hirsuta). This cousin - once removed?-  from Europe also pops up in December.  Small rosettes form in slight openings in the lawn, taking advantage of the smallest amount of light. The seeds of this annual were dropped the spring before. I pull every one that I can find, stuffing them into my pockets until I can get inside to trash them. As the weather warms, they pop up faster and faster, seemingly forming slender seedpods – exactly like their other mustard family relatives – almost before I saw their tiny, four-petaled flowers. Argh!

A plateful of hairy bittercress, most of which is going to seed;
if you want to eat it, pick it just before it flowers to get the most foliage.

In the shaded areas of the yard, another favorite is blooming while its cousin also torments me. Starry chickweed (Stellaria pubera) is a lovely native perennial with medium-sized, white flowers in late March and early April.  I love to tell people about this beautiful plant.

Stellaria pubera flower on left; S. media on right
Unfortunately, hearing the name ‘chickweed’ reminds people of its annual cousin, Stellaria media. This pesky weed shows up in the lawn and flower beds. I try to recognize it early and pull it out, but I suspect that I leave a few roots behind to grow again. Argh!

For comparison, I've posed the two flowers side by side; surprise, the native species is much showier!

I suppose I should just give up and make the best of the situation. Both of these weedy relatives are edible. Read more about eating chickweed here and hairy bittercress here (complete with recipes). 

Stellaria media sprawls out from the center

Non-native Cerastium glomeratum

If you’ve heard about the native bittercress (Cardamine pensylvanica), this page has a good description of how it’s different from C. hirsuta.

So hit the road, weedy relatives, and don't let the door hit you on the way out. Be sure to take your even more distant non-native cousin sticky chickweed (Cerastium glomeratum) with you!

Sunday, March 17, 2019

So You Want to Support Pollinators – Part 3


This is the last in a 3-part series on changing at least some of your landscape to support pollinators. The first part (here) was about understanding the benefits of doing so. Last week we covered ‘how to start,’ which included evaluating your space and researching/choosing your plants. As we head into the season of spring native plants sales in Georgia, you’ll want the list of plants you’ve chosen handy. 

You’ve picked your spot and figured out how much sun and moisture it has. You’ve researched your plants and made a list of what you plan to use. Now it’s time to lay out the design. Here are some things to consider:

Grouping plants: Bees, in particular, are better supported by groups of the same plant. Rather than plant one of twenty different things, include 3-5 of each species and plant them in a group so the pollinators can move from flower to flower. Grouping is also more aesthetically pleasing to humans so your design will be attractive to your neighbors as well. Knowing the mature size of the plant will allow you to place them far enough apart to give them room without going further than necessary. For a fuller look, plant closer together but recognize that you might adjust (i.e., move them around) as they reach mature size. Draw out your design on a piece of paper so that you remember what you planned when it comes time to plant.

An example of a design where each number represents a different type of plant

Leave space for ground nesting bees: Leave a few bare areas off to the side so that ground-nesting bees have a safe place to make their nests. These aren’t yellow jackets that I’m talking about, but small, solitary bees that provision for a few eggs and then leave the larvae to grow up on their own. See more information at this link and good pictures at this link.

I noticed this ground-nesting Colletes bee in 2014

Now you can buy your plants! Here are some things to consider:

Source: buy from reputable native plant suppliers, including special spring sales that groups use for fundraising and small, local nurseries who are trying to make a living by growing native plants.

Size: perennials usually come in quart and gallon size; consider the value for what you’re getting, check for bloom buds (know that quarts may not bloom the first year but you might be able to buy more of them) and good root growth. A gallon-sized plant might have just been stepped up from a quart and isn’t any older than the cheaper quart.

Pesticides: ask if the plants were grown with neonicotinoid pesticides; these are harmful to insects and can even have residue present in the nectar and pollen as well as the leaves for the first year. We don’t want to attract pollinators only to harm them.

Prep the ground just before planting by removing any weeds or grasses, amending with compost if you like, and leveling or mounding the ground to fit your design. Install the plants so they are no deeper in the ground than they would have been in the pot (don’t over-dig the depth of your holes or they may sink after being watered). Lightly loosen the roots if they are bound and spread them to the sides to encourage them to explore their new home. Gently press the soil around each plant to reduce air pockets.

I also like to include a few rocks for butterfly basking and for small lizards/salamanders to hide under.  You might even do a puddling station for the butterflies. Adding a tall stick/pole is helpful for dragonflies that might like to visit (and eat a few mosquitoes). Modest amounts of untreated mulch/pinestraw (don’t use the colored mulch, it has chemicals) help retain moisture but leave some un-mulched areas on the edges for ground bees. Water your plants after planting.

Protect your new garden from the harsh realities of nature! Water your plants as needed the first summer and fall if you don’t get sufficient rain. Protect from any deer as needed; I use Liquid Fence but there are other protects and methods to deter them.

The next step is the fun part: Observation! Keep a journal to record what you see, what is doing well, what you wish you had more of, or what did poorly. By sharing your experience with others, you might get more ideas for plants to add in the fall (more native plant sales!).

Left: Southeastern blueberry bee, Center: Tiger swallowtail (dark form); Right: Longhorn beetles 

Here are some specific maintenance tips to consider going forward:

  1. Re-evaluate during the blooming season if your thoughts on light and moisture turned out to be not quite right (too much or too little).
  2. Re-evaluate for quantity and placement of plants (are the big ones crowding out the small ones, do you need more milkweed).
  3. At the end of the season, lightly tidy as needed but leave as many stems, seed heads, and foliage as you can; these harbor small insects for birds to eat during the winter. They may also contain the chrysalides of butterflies.
  4. Come spring, clean up foliage but leave 10-12 inches of stems from the bigger perennials. Stem-nesting bees will use them to harbor the next generation: the year of 2019’s living stems are used in spring of 2020 to make nests and those bees will emerge in spring 2021 (see my previous blog here). I take any foliage that I remove and lightly create a stick pile in a shady area; that way any bugs have a chance to safely emerge.
Have fun, learn from your mistakes, and shout your successes for new people to learn.

Newly planted area in 2014; it is now overtaken by tiny asters and this
Penstemon smallii is nowhere to be found in this bed! Things grow and change.


Sunday, March 10, 2019

So You Want to Support Pollinators - Part 2

Leaf cutter bee on Rudbeckia fulgida
Last week I wrote about understanding the benefits of changing your landscape to support pollinators. I laid out the basics of the concept: knowing the difference between needing food (larval host) plants and nectar plants. If you missed that post, you can find it here. This post is about How to Start, specifically evaluating your space and choosing the plants.

For those of us in Georgia, now is a great time to be planning. Spring native plant sales start in about 2 weeks so you’ll have plenty of opportunities to pick up the plants you chose for your new space. Before we pick out any plants, however, we’ve got to understand the space. The two most important considerations are the physical conditions of light and moisture.

Light – the range of light varies with the location (North-facing, South, etc.) as well as any nearby tree canopy. Most pollinator gardens want to maximize blooms so we’ll want a location that gets good sunlight. Full sun conditions are defined has having 6 or more hours of fairly direct sun each day. Whether you get sun hours in the morning (the kindest of lights) or the afternoon (harsh light) or a combination of both, the total hours in the growing season (when nearby trees have leaves) needs to be at least 6.

You can measure your light in the area on a sunny day when you are around all day. A clever method that I read about has you put down a marker for every hour that you go outside and the area has full sun; you can use popsicle sticks, utility flags, marbles or even just mark it on a piece of paper. Go outside at the same time each hour and check. Then count up all your markers to get the number of sun hours. If the area varies (half of it gets 6 hours but the other half gets 5, for example), then make a note that you might be choosing part-sun plants for the shadier half.  You may have to re-evaluate during the blooming season if there are a lot of trees that cast more shade than you thought.

Moisture – while most basically broken down in wet and dry, we know that there are places in between those two extremes. There are locations that are consistently moist, others that are soggy after a rain (but dry out later), and some places that are generally average-to-dry all the time. This is hard to evaluate in a day; you’ll need to have a longer period (or perhaps you already know).

Turtlehead (Chelone glabra) is good for wet spots and bees love it

Once you’ve evaluated the physical conditions of the chosen site, it’s time to pick the plants based on those conditions and the pollinators that you want to support. My recommendation is that you choose your plants based on no less than 4 points: light requirements, moisture requirements, appropriately native to your area, and bloom time. If you have a specific pollinator goal (e.g., you want to support Monarch butterflies), then add a 5th point for that goal.

Silver-spotted skipper on wild bergmot (Monarda fistulosa)

Two of those points need further discussion: appropriately native to your area and bloom time.

Appropriately native – these are plants that you know are native to your area whether it is the Piedmont region or the Coastal Plain or the Mountain eco-systems. These plants evolved with the insects in your area and, in the case of butterflies in search of larval hosts, will likely support what’s flying around. For example, gardeners in the Piedmont aren’t expecting to have the deep south-based Palamedes swallowtail butterfly visit so would not plan to include red bay (Persea borbonia) as one of their host plants. You can research ranges for certain plants using USDA, BONAP, and the Georgia Herbaria.

Bloom time – good pollinator support needs flowers during all 3 seasons: spring, summer, and fall. Luckily, we have a good selection of native plants that bloom in all those seasons. Please don’t forget the fall, especially if you want to support migrating butterflies like Monarchs. They need those flowers to power their trip back to their overwintering locations. Goldenrods, many of which are well-behaved, are an essential part of fall blooms.

Golden ragwort (Packera aurea) is an early bloomer

While I certainly put most of my emphasis on native plants, some non-native flowers are heavy bloomers and might be included as part of the mix in your garden to add extra floral power. These include plants like zinnias, tithonia, and pentas as long as they were grown without pesticides. Other people like to include the non-native herbs parsley and fennel as host plants for Black swallowtail butterflies (note: Black swallowtail is the only butterfly that uses it, not ‘all swallowtails’).

In March of 2014, I published a blog with 3 full lists of seasonal native plants for North Georgia. Here is the blog if you want to read it, or use these direct links to the 3 lists:


Here’s an example of a plant that I would choose for my garden with all 5 points considered: Black-eyed Susan (Rudbeckia hirta) is a full sun, average/dry moisture, native to my area, blooms in summer (late June into early August), and supports small bees and small butterflies.

I hope you are now on your way to evaluating your space and researching your plants. Here are some reference sources for determining host plants for butterflies and moths if you want to support the larval host needs of particular species:

Jaret Daniels’s book ‘Butterflies of Georgia
David Wagner’s book ‘Caterpillars of Eastern North America

Tiger swallowtail on Asclepias tuberosa

I love it when a plant can do double duty, something mostly unique about native plants. Here a dark Eastern tiger swallowtail butterfly nectars on orange butterflyweed (Asclepias tuberosa) which is the larval host plant for Monarch butterflies.

The next (and last) installment in this series will be about implementation and maintenance; look for that post next week.



Sunday, March 3, 2019

So You Want to Support Pollinators – Part 1


As more information becomes available about pollinator declines (and insects in general), people are inspired to think about how they can make changes to their landscapes in support of them. I’ve agreed to give a talk this summer about this topic so, if you don’t mind, I’m going to use the next several blog entries to flesh out what to say to people who are eager to listen.

Monarch on blue mistflower (Conoclinium coelestinum) in the fall

Benefits – people want to know why it’s worthwhile to put the effort into choosing specific plants for pollinators. What pollinators are likely to benefit? Is there any other reason to consider doing this?

  1. Bees – while many flowers can support bees, there are some flowers that especially support native bees and others that are more nutritious and healthy for bees in general.  I loved finding the southeastern blueberry bee in my garden several years ago. In addition, the concept of native bees as distinct from honey bees is getting more attention. Besides what you plant, your pollinator garden design can increase your support of native bees.
  2. Butterflies – adult butterflies enjoy many flowers while butterfly (and moth) caterpillars have more specific requirements and these requirements are usually native plants. If you’d like to have more butterflies swirling around your garden, planting what the caterpillars need is a way to keep ‘em coming.
  3. Birds – supporting birds is a bonus side benefit of pollinator gardens. Seed-eating birds like goldfinches are grateful that you planted coneflowers and sunflowers. Insect-eating birds (and parents with hungry chicks) enjoy some of the bugs (that is, pollinators) who visit your garden.
Megachile bee on Rudbeckia
Southeastern blueberry bee





















Basics – it all comes down to several key choices when deciding how to populate your pollinator garden. You’ll want food and shelter. When it comes to food, you’ll want it to be pesticide free and you’ll want a selection of both host as well as nectar plants. I like to say that the nectar plants bring them in and the host plants convince them to stay (and lay eggs). Plant choice makes a difference:

  1. What are host plants? Another term is ‘food’ plants and they are the plants on which butterflies, moths and other bugs will lay their eggs. One of the most well-known examples is the Monarch butterfly and its host plant milkweed (Asclepias sp.) and related plants in the milkweed family (Asclepiadaceae). You have two options for where to locate your host plants:
    1. In your pollinator garden – these are chosen specifically to be a part of your pollinator garden and are usually perennial plants: the milkweeds for Monarchs, the pussytoes for the American ladies, pea family members for skippers, passion-vines and violets for fritillaries, etc.
    2. Near your pollinator garden – these include trees and shrubs that are located in the area around your garden: spicebush for spicebush butterflies, sassafras and tuliptree for tiger swallowtails, plus oaks, cherries, elms and others.
  1. What are nectar plants? These are the flowering plants. Some might flower only in one season (spring/summer/fall) but return each year so they are considered perennials. Annual plants may flower throughout several seasons and are generally showier. Over time you might observe that different bees and butterflies like different flowers; this is usually because of the length of their tongue:
    1. Short-tongued bees, small bees, and small butterflies like skippers use smaller flowers and flowers with shorter floral tubes. These include the flowers of milkweeds, asters, goldenrods, coreopsis, sunflowers, mints, etc. Some flowers are simply for crawling inside: turtleheads and penstemons make for great bee-watching as bumble bees scoot in and out of the flower itself.
    2. Long-tongued bees and butterflies with long proboscis (as well as hummingbirds) prefer flowers with long tubes like cardinal flower, sages, native azaleas and vines like native honeysuckle, crossvine, and trumpet creeper. 
    3. You'll want a variety of flowers to satisfy different pollinators.
Bumble bee shares coneflower with caterpillar
Andrena bee on hawthorn





















Next week we’ll talk about How to Start, including evaluating your space and conditions as well as choosing your plants. Part 3 will cover implementation.