Nothing tops a flowering perennial plant in a Texas garden. Forget annuals. Go with perennials. They come back year after year and can be very drought tolerant depending upon the variety and once established. They also are nature magnets, create great color, and can be very fragrant. You can also get some great cut flowers for a bouquet from some of these plants.
I have been growing flowering perennials for many years now in North Texas, and I have developed several personal favorites. A plant earns my attentions if it has a long flowering season and is hardy and drought tolerant. I am also always looking for perennials that are fragrant and will attract butterflies and bees.
Some landscapers determine perennials based upon color scheme and complimentary colors. Personally, I like to combine a lot of different colors. However, I do have a tendency to gravitate toward blues, pinks, lavenders, and white.
Below are a couple of photographs of two perennial beds that I installed in the front of my house last year. This bed has been in place for one year and still has yet to mature. Within one or more years, it should be a single, non-stop bed of flowers with no mulch showing. These photos were taken after several weeks of 100 degree heat with little rain. The plants are suffering a little, but they are still holding up fairly well.
In the first beds you can see the low growing Homestead Purple Verbena (front), Magnus Purple Coneflower, Walker's Low Catmint (right side of photo), Sunny Border Blue Speedwell (between the verbena and coneflowers), Autumn Joy Sedum (not blooming, small plant behind the verbena), Purple Liatris (barely seen behind the confeflowers), and Becky Shasta Daisies (barely visible behind the liatris).
Below is a list of my favorite perennials ranked from first (being my most favorite) to last. There are no real surprises here because most, if not all, of these plants are award winners and carried by many Texas nurseries:
1. Walker's Low Catmint: I love this plant. It is a mounding, mid-sized plant that I like to put at the front of a border. I particularly love this plant because it blooms non-stop from March until November. It has blue flowers that grow at the ends of arching panicles or racemes, and the flowers attract bees and butterflies. The leaves are fragrant to the touch. This plant is very hardy. It will typically grow one to two feet high, and is spreading to two to two and a half feet wide. It can be kept tidy and in check through mid-season shearings. I think this plant looks best in a mass planting along a row.
2. Magnus Purple Coneflower. Another beautiful, hardy plant for Texas. This plant will bloom through much of the season, from late April until early November. You will need to cut off the spent blooms to encourage re-blooming. It's blooms are pink and shown in the photograph below. The flowers are fragrant if held to one's nose and attract butterflies. These plants re-seed and spread very well. The flower stalks will often reach two to two and a half feet tall.
3. Sunny Border Blue Speedwell. This is another perennial with a really long blooming season. They bloom from April through October for me. The beautiful blue flowers grow in spikes that bloom from the bottom up. Over the season, the flower stalks keep growing and growing up. Once they start to get rangy, I will often cut them back somewhat, and they start growing right back. You can see what the flowers look like in the photograph above. These plants start fairly compact and rarely get taller than two feet for me. Hence, I like to use it as a second level plant in between the short front row and taller plants in back. Bees and butterflies also like this plant.
4. Becky Shasta Daisy. This is a very vigorous and hardy form of white daisy. It grows to one and a half to two feet tall and is spreading. It has a shorter bloom time than the previously mentioned plants, but it is still one of my favorites. It usually will flush with beautiful white flowers from June through July, and then with dead-heading, it will continue to flower less heavily through the summer. Bees and butterflies also like to rest and dine on the large flower heads of this plant.
5. Homestead Purple Verbena. This is a low growing, spreading plant. It will not grow taller than one foot, so it is perfect for the front of the bed. It has pretty purple flowers as its name suggests. It is one of the first perennials to flower in the spring blooming heavily for a month or more. It blooms intermittently in the summer, and then it blooms heavily again in the fall as temperatures lower. This is a hardy verbena that is well suited for our zone 8 winters. Many verbenas that you find in nurseries will not make it through our winters.
6. Nanho Purple Butterfly Bush. This plant is more of a bush than a perennial; however, it does not have much structure, so I treat it more as a perennial to go in my flowering perennial beds. There are dwarf varieties of this plant, but those do not flower quite as much. The regular varieties can grow to four feet tall in my experience, so you have to give them room. I like to plant Walker's Low Catmint or Homestead Purple Verbena around their base. This is an interesting plant with many attributes. I think it is one of the most fragrant perennials for Texas gardens. When in bloom, you can smell its blooms from ten feet away. The blooms have a wonderful vanilla scent. The large blooms are also magnets for some of the larger butterflies such as swallowtails and monarchs. It also attracts hummingbirds in the spring and fall. This plant will have a huge flush of blooms in late Spring (late April or May), and then bloom sporadically throughout the summer and into the fall. It has a tendency to bloom for a couple of weeks, sit with spent flower heads for a couple of weeks, then bloom for a couple of weeks, then sit again, etc. You can speed up the reblooming process by cleaning the spent racemes off the branches, but that is a lot of work. Thus, I usually let the flowers regenerate on their own.
7. Firewitch Dianthis. This is not a very ornamental plant in that it is very low growing to only six inches and has a mounding habit. I think it is best grown in multiple groups of six or more plants, in the front of the bed. This plant is fairly heat and drought tolerant. It is at its best in early spring and fall when it they are filled with a profusion of dainty pink flowers. The real magic of this plant is the heavenly scent of its flowers. You will walk through your garden in the morning and in the early evening and smell its intense, richly sweet smell, and you will wonder from where that smell is coming. You can smell these plants from twenty to thirty feet away when in full bloom. They really are amazing in this regard and a necessity in any fragrant garden.
8. Blue Fortune Hyssop / Agastache. This is a great plant that flowers from April through November with a profusion of light blue spikes of flowers that are bee magnets. This plant looks great planted next to Magnus purple coneflowers. The leaves have a light, minty smell that can be used in teas. It needs its space and can grow from three to four and a half feet tall by the end of the year. This plant is shown in the photograph below.
In truth, I love all agastaches. They are almost all very drought tolerant. Many agastaches have wispy flowers growing to three to five feet tall. Because they are a wispy plant, I like to grow them mixed in with other plants like liatris. High Country Gardens Nursery sells a lot of different agastaches by mail order.
9. May Night Salvia Nemerosa. I love salvias. I find many perennial salvias, like autumn sage salvia greggii, can get rangy and require frequent pruning. However, salvia nemerosa is a low growing salvia that is good for the front of a border. Its flowers grow in long blue racemes. It is heat and drought tolerant. I typically find that this plant will flower heavily in the spring and fall, but only sporadically in the summer.
10. Purple Liatris. This plant does not have a long bloom time in my experience, but it is still worthy to be in your perennial bed mixed in with your other tall perennials. It grows to three or four feet with beautiful purple spikes of flowers that bloom from the top down. Butterflies and hummingbirds like this plant. It typically blooms in May and June in North Texas. A photograph of this plant is shown below.
11. Goldsturm Black Eyed Susan. This is a tough plant that has pretty yellowish-orange blooms that look similar to daisies in shape. It grows to approximately two and a half to three feet tall. In my experience, it typically blooms from June to July.
12. Autumn Joy Sedum. This is a good plant for additional, subtle late fall color. It is very pedestrian throughout the year until October. In the fall, it develops large flat-headed bracts of flowers which bloom once the temperatures drop. It has soft pink flower heads that grow to approximately one and a half to two feet tall.
13. White Flowering Tobacco / Nicotiana. I really love this plant because of its intense evening fragrance. It is not a very shapely plant. It grows in a mounding fashion to about one and a half feet tall, but it then releases tall protrusions of white flowers that can reach three feet tall. I think it is best suited in the second row of a perennial bed. Planted in groups of three or more plants, these plants come to life at dusk. They emit a rich vanilla smell that can be sensed from across the garden up to twenty or more feet away. Although these plants are not considered to be cold hardy, I have had very good luck with them returning every year for me, and they will also re-seed.
Below are few photographs of two new perennial beds that I planted this spring around the perimeter of vegetable garden. These plants are interplanted among kiwi, cherry trees, and peach trees. As you can see, these perennial plants are still very immature and have not filled in. They have a long way to go. Some of the plants have had a difficult time getting established this summer with the drought, but the majority of them have done well. I am confident that these will fill-in next year to become a colorful and fragrant safe harbor for all of our beneficial insects.
Here are a few more perennials that also have found their way into my perennial beds.
Autumn Sage. This is a fine plant that blooms most vigorously in spring and fall. It needs a lot of room, and it requires frequent prunings to stay tidy. It comes in red, pink and white.
Sculleteria. It is a good front of the border plant in that it rarely grows taller than one foot. It blooms throughout the summer, but the blooms are very small and subtle. It can be a good change of pace for the front of the border.
Mexican petunia. This is another low grower that comes in white, pink, and purple. It can be a vigorous spreader. The plant looks somewhat like low growing monkey grass, with pretty, bell-shaped flowers.
Mexican bush sage. This is a fall blooming perennial that can grow from three to five feet tall. It is for the back of a perennial bed.