by Larry Hurley, Perennial Plant Buyer

Or, perhaps we should say Tuin Up; I believe Tuin is Dutch for garden. By mid-summer, much of your garden is feeling a little dragged out. Hot days and warm nights are tough on plants as well as people. A little pruning back can be just the ticket to rejuvenate annuals and perennials. I’m not your guy for vegetable garden hints, I have a shady yard.

Let’s start with hanging baskets. A couple of things happen over time, both a factor of the concept that, if a plant is still alive, it’s trying to grow. (That which doesn’t kill it, makes it longer.)

Hanging Baskets: Basket plants should be sheared or selectively pinched to keep them in proportion to the pot. Petunias, for example, will trail down the side of the pot, growing and flowering from the ends of the stems, until you have flowers at the end of 18 inch long stems with few leaves or flowers at the top around the basket.

The best thing to do is selectively cut off about 20% of the stems each week or two right at the edge of the basket. As those stems recover and start to grow and make flower buds, you cut the next 20%. Over time, you keep the plant to a manageable length and it never looks like it was cut back. For an upright plant, do the same thing–just pinch random stems back from say 12 inches long to 4 inches long, once every week or two.

As the basket ages, the plants roots slowly fill the soil in the basket. The soil settles, washes out of the pot, decays…at some point you have more roots than soil. Roots don’t hold water like soil does. If you find you are watering a couple of times a day, it may be time to put the plant into a larger container– maybe no longer hanging– or in the ground.

Echinacea Trial garden

Perennials: The best reference is The Well-Tended Perennial Garden, by Tracy DiSabato-Aust. She tells you how and when to cut back or shear plants in your perennial garden in order to control height, or to prepare the plant for another surge of bloom if it’s a rebloomer like most of the summer-blooming perennials are. Tracy is a landscape contractor in Ohio, and the book is written from practical experience and for the average gardener.

Annuals: Cut off old flower heads to encourage rebloom (deadheading) or cut back the plant part way to encourage bushiness and branching (and eventually more flowers). If you are happy with how they look, don’t do anything. Vinca and Supertunias probably don’t need any attention at all.

Herb Container. Photo by Larry Hurley

Herbs: Continue to pinch off the ends of the stems to encourage bushiness. With basil, remove flower buds by pinching out the flowering stems. If you have a few strong stems that have not gone to flower, take a 3-inch- or-so long tip cutting (the end 3 inches of the stem) and put it in a glass of water so that the bottom inch or so is in the water and the top is in a sunny window. It should root in about 10 days. In two or three weeks, you can plant it back outside while your older basil flowers and declines. The water glass should be dark; dark colored, or wrap it in foil. You can do that with coleus, too.

Weeds: Pull them out, they are just going to get bigger and meaner.

One of the easiest and most rewarding things for a gardener to grow is a selection of herbs. It’s fun to use your own fresh herbs in cooking, they are interesting to learn, the most common ones all have the same growing requirements, and animal pests tend to leave them along.

First, cooking. That is when you make your own meal from a series of ingredients instead of buying in at McDonald’s or tossing a frozen bag of pasta into the microwave. Just thought you might want to know. It takes a combination of time and thyme, but on those days when the weatherman has you cowering inside from the elements (Rain today, run for your lives! Hot today, for goodness sake don’t go out there!!), it can be fun to spend some time following a classic Julia Child recipe instead of downloading apps onto your I-phone. But that’s just me.

Anyway: more on herbs as I understand them. Spices and edible herbs are used for flavoring food. Spices are tropical, are often seeds, and often come from trees, shrubs or vines (pepper; cinnamon which is tree bark; vanilla which is the seed pod of an orchid). Our common herbs are more temperate in origin, and look like your standard garden plant, sometimes annuals, usually perennials.

Just because something is called an herb DOES NOT MEAN IT IS EDIBLE. Herb usage was traditionally medicinal, the province of shamans, monks and witches; the flavoring aspect was just a byproduct. (Take two leaves and call me in the morning, if you’re still alive.) Example: Rue is one of the herbs that is usually sold at garden centers. It’s a pretty blue-leaved plant, but can cause a dermatitis reaction like poison ivy on some people (you will rue the day…). So, once you step away from the common herbs like basil and thyme, Google that bad boy before you throw it in the soup.

Right off, I can’t think of any that are North American in origin; they often come from the Mediterranean area, basil originally from India I think. On the whole, they do best in full sun and need good soil drainage. The flavoring frequently comes from oils that develop most strongly in hot weather. That’s why your basil tastes better in the summer than in the winter. When dried, some herbs hold the flavor, others lose it, especially the leafy herbs. That’s why dry basil and parsley are not as good as say, dried rosemary.

Harvest your herbs early in the day for best flavor. Growing them on a sunny windowsill? Some herbs are okay in a south window, but especially in winter, it’s going to be tough to have enough light for them to thrive or develop much flavor.
The strong flavors of herbs should repel deer, so if you have deer problems, try planting some sage or thyme. Let us know if they graze on your basil. We keep lists.

A good place to see herbs in action, so to speak, is at the huge herb garden at the National Arboretum in DC. Depending on what they have going on this year, will be able to observe things like which lavenders or rosemary varieties do better in our climate, and which herbs are more ornamental. The herb garden is near the visitor center and the Bonsai pavilion. The Arboretum is free, of course, and well worth a trip any time of the year.

For beginners, basil is a great plant, and can easily be grown in a pot on a sunny deck. It is an annual, it grows fast, and you harvest the leaves and soft tips. As the summer progresses and the plant matures, clip off the flower spikes and discard them. Make your own pesto. Probably okay to plant now. They are notorious for rotting off at the soil line in cool weather.
Also easy to grow: parsley (grow as an annual); dill (annual); fennel (seeds out badly, watch out for this one); chives (perennial); thyme (perennial); sage (perennial); oregano (perennial); and French Tarragon (perennial).

Rosemary and lavender: perennial but touchy; siting in good drainage is critical, and for rosemary, some varieties are more winter hardy than others. We have a huge rosemary shrub at the exit at our garden center in Beltsville. It is in a raised bed with great drainage, and has the heat of a poorly insulated building for company in winter. Here’s hoping you try some herbs this year!

Herbs in Pots and Containers

Thinking of growing your own fresh herbs? Thyme is one of the easiest herbs to grow, as French Thymewell as one of the most versatile. Like most herbs, it is best planted in full sun and needs well-drained soil. It grows well in containers, too.

During the first year, harvest sparingly. Leaves can be harvested throughout the summer by cutting stems, but the flavor is best just before flowering. To dry, cut stems just as the flowers begin to open–dried thyme retains its flavor better than many herbs.

'French' Thyme

Slow to release flavor; thyme is usually added early in the cooking process; but it is a strong flavor, a little goes a long way. When cooking, use 1/3 as much dried as fresh thyme. In the garden, or in pots, thyme mixes well with lavender, rosemary, basil, and oregano.