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My thumb nail gets a lot of work. There are few plants I can walk past without pinching. This goes double for annuals.

Pinching off the top encourages side branches to grow out and creates a fuller plant.

The science behind this is based on hormones. Removing the growing tip from a plant causes a chain reaction. In a normal situation, auxin travels from the top of the plant where it is produced downwards towards the roots. It suppresses the side growth of the buds. Pinching the growing tip removes the auxin allowing the side branches to grow out, creating a bushier plant.

Some plants benefit from a pinch more than others. Snapdragons, salvia, petunias, verbena, callibrachoa, anagalis, bidens, gaura, and lantana get pinched. In the perennials, dianthus, phlox, gaillardia, nepeta, leucanthemums, salvia and veronica all get a hard pinch.

Other plants are not helped by a pinch. Things that are naturally tall, like sunflowers, iresine, and psederanthemum do not respond well to a pinch. In this situation, a central leader is preferred.

There is a difference between removing dead flowers and pinching the growing green tip to create a bushier plant. Removing spent flowers will encourage a plant to keep blooming, instead of putting energy into seed production. Deadheading will do little to affect branching.

Pinching a plant back will delay flowering, but will increase total number of flowers by creating more blooming stems.

Which brings me to hanging basket and pot care. Baskets purchased for Mother’s Day may become sprawly in the summer, or out of balance. Cutting back leggy members creates a fuller plant and put a basket back into harmony.

Baskets and pots also benefit from a good shot of liquid fertilizer. If you see lower leaves beginning to look yellow, a good watering with your favorite liquid feed will do wonders. New growth steals nitrogen from older leaves, causing them to look yellow. Supplementing with a liquid feed will green them up again.

However, this is a situation where too much of a good thing can hurt, however. Too much fertility can burn roots, or cause extra vegetative growth at the expense of flowers.

Baskets could also need freshening up if cold season annuals like pansies or nemesia are looking peaked. Hot-weather-lovers like pentas, lantana, evolvulus or petunias would be happy to take their place.

Cutting back spring-blooming perennials now is also good for their health. If you have mountain pink, dianthus or candytuft with unattractive seed heads sticking up, a good shearing will promote a fuller plant. In my garden the catmint has been blooming for about a month and is starting to open up in the middle. I’ll cut it back in half. This will make it bushier and bring on another set of blooms in about three weeks. Cutting back summer bloomers like plox, agastache, or monarda that have gotten too large will help them bush out.

Now is also the time to cut back asters and mums to about a foot. Have it done by the fourth of July and you won’t lose the fall bloom.

I think we can all agree it was a terrible winter and we are happy that spring is finally here. We can also agree that most of the butterfly bushes, hydrangeas, figs, crape myrtles, flowering cherries etc took a beating. Not to mention evergreens. That is a topic for another week.

We have been fielding lots of call the last month about whether to give up on the above and cut them down and/or pull them out or to keep waiting.

If you see green at the bottom, it is not dead- might have merely died back the ground. Crape myrtles in this area typically die back to the ground the first several years they are in a landscape. For crapes and butterfly bushes this is not a problem, because they bloom on new wood- cut the old stems if you are tired of waiting and call it “rejuvenation pruning”.

We have several old crape myrtles with thick knarled trunks, and lovely exfoliating bark on the farm. I didn’t have the heart to cut them down, and sure enough, most leafed out last week. Not fully, but enough to convince me to keep the chain saw in the garage.

Hydrangeas, at least the pink and blue mop head types, get their first round of flowers from buds set last fall. If there is only green from the bottom, you may have lost this year’s flowers. The reblooming types will still reward you with flowers on this season’s growth.

The hydrangea below our deck has only bloomed two years out of the last five. It has a few green leaves at the bottom, but the stems snap and show no green wood. I think I’ll pull it out and replace it with something slightly less precious.

Another late-leafer is the hardy fig. We have a fig tree across from the store sheltered on one side by a large crape myrtle, and to the back a greenhouse. The last two years it has been beautiful and given us tasty figs. Still no sign of life. If it hasn’t leafed out in a few weeks, I’ll pull it out.

Many of the shrubs on our property made it through unscathed. Our Korean spice bush (Vibernum carlecephalum) had huge fragrant flowers when I was still making the kids wear hats to school. The fringe tree (Chionanthus virginicus) is currently perfuming the whole yard with its beautiful flowers.

I am willing to be patient with the slow-leafers. They are on the northern side of their range, and straining the bounds of hardiness. I don’t blame them for being hesitant, but I’m not willing to wait forever. There is always something else to take their place.

After last week’s torrential downpour, I’d thought I’d touch on the topic of rain gardens. Rain gardens have been gaining in popularity for the last several years as people are becoming more concerned with the sustainability of their gardens and lifestyles. Especially as protecting waterways and the Chesapeake Bay come to the forefront politically and environmentally.

Rain gardens are areas in the landscape planted with deep-rooted perennials. Often situated on a slope, these areas act as a catch basin and slow the runoff from roof, driveway, or sidewalk. The deeply rooted perennials filter the water ultimately assisting it back to the groundwater instead of a sewer. They also trap pollutants- in this area, commonly the nitrogen and phosphorous that wash from farm fields.

If you have soil erosion damage to your yard, particularly near downspouts or driveways, or you have standing water for several days after a rain event, you may want to think about planting a rain garden.

Rain gardens should NOT be situated in the lowest spot in your landscape- it should drain within 2 days of a heavy rain. Standing water to that extent acts as a breeding ground for mosquitoes and can be a health hazard. Rather, plant a rain garden on a slope near a problem area. An oval or kidney shape twice as long as wide is good to catch the most runoff. The website raingardenalliance.org is a fantastic resource for planning and site preparation.

Plant choice is also important. Don’t think only wetland plants, because a lot of the time this garden will be dry. Think deep rooted perennials, sedges and possibly shrubs that will add ornamental value, and attract pollinators to your landscape as well. Natives like Joe Pye weed, asters, liatris, blue flag iris, Culver’s root, bee balm, milkweed, switchgrass, black-eyed Susan, and sedges do exceptionally well in a sunny rain garden. For partial shady areas, add cardinal flower, Virginia bluebells, Jacob’s ladder, rue or spiderwort. Ninebark, viburnum, and red-twig dogwoods are great woody additions.

If you want to get really elaborate, extend your downspout to reach your garden, or build a swale lined with rocks or sedges to divert water to your garden.

There are fantastic examples of rain gardens planted both at Mt Cuba center and Longwood Gardens. North Creek Nursery, a local wholesale plant propagator, has an expert on rain gardens on staff, Claudia West, who has been doing extensive workshops around the area helping to educate homeowners and landscapers in this area. If you are interested in learning more, Claudia will be hosting a workshop at the Native Plants in the Landscape Conference held at Millersville University from June 5-7th.

We all need to do our part to help reduce erosion, and protect one of our most valuable resources- clean water. There is no reason it doesn’t have to be beautiful too.

Photo credit: David Hymel, Rain Dog Designs

Nature provides an amazing interaction and interdependence between plants, worms and birds. Let me correct my mistake. The worms we see on plants aren’t real worms but caterpillars, the larvae form of butterflies and moths.

Locally we could encounter over 100 different butterflies and over 2500 different moths. Each female of each of these lay dozens, if not hundreds, of eggs anxious to hatch as the weather warms. That’s true, but painting with a broad brush because there are a few exceptions.

Spring also brings a rush of new plant growth just as the hatching caterpillars are looking for something to eat. In your garden, if you see a plant in trouble, remember that insects attack new growth. If the problem is with older leaves, you have a disease or nutritional problem.The oak trees in our yards or forests top the list of caterpillar favorites. One study suggests that an oak can attract over 500 different caterpillars. They top the list but are not really special, since there are many plants that host more than 100 species.

Enter the birds. For many song birds migrating further north, the caterpillars provide fuel for the trip. For those that stay and raise their young here, the caterpillars provide a high protein diet that provides rapid growth to their offspring. Lots of young song birds go from egg to flight in two or three weeks.Interestingly, the migration or return comes in waves over almost two months. I guess the later arrivals like older and bigger caterpillars.

The battle is not one sided. Most caterpillars feed at night and hide during the day so the birds must work for their meals.If you watch birds, you will eventually notice that birds feed at different spots. Some work the tree trunk. Some the inner branches. Some along the edges. Some near the ground. Others at the very top. That way the whole area is covered and the birds are not competing with each other.That works early in the season, but after the young have fledged the birds seem to scatter. Why?

By early summer the plants have had time to manufacture insect defenses in their mature leaves reducing insect pressures.An example of plant defenses would be the caffeine produced by the coffee plant. It is an effective insect deterrent if you are a coffee plant. Another is the monarch butterfly who, as larvae, feed exclusively on milkweed. The toxins in the milkweed travel with the larvae into the adult butterfly making them unpalatable to birds. Few other insects bother the milkweed.

Plants provide food for the caterpillars of which a few will survive to be moths or butterflies to restart the cycle the following year.The plants are spared defoliation as a high percentage of the horde of caterpillars is eaten.The birds get high quality food to feed their young or fuel for additional migration. Nature makes only winners in spring and that can include us too, if we take the time to notice and enjoy.

A decade ago I filled space in two consecutive issues explaining everything I knew about hydrangeas. Maybe it’s time to revisit the subject.

Much hasn’t changed. There are still several species with large white flowers that form large shrubs or with extra work will grow into small trees. Grandmother left the old farmhouse with two hydrangea trees near the front porch. I remember cutting flowers for my mother and, of course, they were starter trees for a small boy who liked to climb.

For a large shrub I like Limelight. In a dozen or more years at a difficult site, it only faltered once during a six or eight week drought. It was not watered. I’d use one of the larger ones if I was thinking trying to form a tree.

Arborescens and oak leafs are two native hydrangeas. The former will handle almost total shade. The oak leafs like some shade but are tolerant of most conditions. In a cold, windy spot I have seen some reduced growth andan occasional flower bud killed in our most severe winter.

Color makes the mop-heads and lace-caps popular choices in any garden. Here I need to stop and offer a disclaimer. I think we are on the northern edge of their bud hardiness. Over the years I have seen a lot of cultivars that were rated Zone 6 fail to bloom after our winters.There are a few old time varieties that are dependable. They seem to have disappeared from the market place.I suspect you could sneak a few stems and roots from an establishedbush with no impact.The rage in the industry today is the re-bloomers. To my new yard, I have added about eight cultivars that I would judge to be promising. The plants were young (small) so reasonable conclusions are still a year or two away.

However, if they even bloom after this winter they will be keepers.There was an exception.I paid the premium price and got one plant of the cultivar Endless Summer. It was a larger plant and had nice blue mop-head flowers when it went in the ground in June. It never stopped until November. The last few November bloom attempts were on the white side of pink. Was it the cold or was it ph?

I don’t know. My yard is full of oak trees, survivors in a wooded lot, which should suggest rather lower ph. My yard grass, not a high priority yet, suggests the same thing.

Historically, soil ph determined whether a plant bloomed pink or blue. My brain crutch remembers blueberries which like low ph. Thus low ph produces blue and higher ph produces pink. In our soil that makes pink easy and blue requires treating the plant as an acid lover. Does it matter to the new cultivars? I don’t know.

That’s it. In ten years I continue to find that the more I learn (think I know) about any subject the less I really know. Maybe, if I remain a student of the garden,in another ten years I can get this down to a single paragraph.