Rosemary- Spending the Winter Inside

After posting a Tuesday Trivia about Rosemary on the Penn State Extension Master Gardener Facebook page, member Jai Cee asked about overwintering rosemary in Centre Co., PA. Here's some information I copied from a previous Master Gardener post.

Flowering Rosemary Indoors at Barb P's house

Master Gardener Barb P. shared photos she took of the flowering rosemary plant in her sunroom. This reminds me about overwintering rosemary outdoors in our area. See more information at this link. But what about bringing it indoors?

Another photo from Barb

Bringing rosemary (and other herbs and plants, typically tender perennials) indoors for the winter requires some different attention than when they were outdoors during the milder seasons.

Rosemary in a container outdoors in summer. (C. Kagan)

OUTDOORS TO INDOORS

Because rosemary does not overwinter well in our area, it is advisable to treat it as a container plant which makes it infinitely easier to bring indoors. However, if you have rosemary planted out, you may pot it up using appropriate potting soil (not garden soil) and pot size with a drainage hole and tray. Follow recommendations about preparing your plants to bring them inside.

If possible, acclimate the plant to the indoors by bringing it inside a few weeks before the first expected frost date, October 15 here in S. Central PA. If you can open the windows and keep the indoor temperatures lows, it will make the transition easier than suddenly bringing it into a warm house.

INDOORS

All I want is for my rosemary to make it through the winter in living condition, so I can drag it back outside when the weather gets warm next year. I have a sentimental attachment as someone special gave it to me.

Fertilizer and Pruning: I don't encourage my rosemary to grow during the winter so I don't fertilizer or prune, except for a snip here and there. Rosemary will go dormant during the winter.  

Light: Rosemary needs 6-8 hours of light as it did outside. A good south facing window may well do but you may have to supplement it with artificial light. A fluorescent light or grow light can help.  Rotate the plant every week or so to keep the plant growing evenly on all sides.

Temperature: As a native Mediterranean, mild-region plant, rosemary will expect cool winters (not freezing) temperatures. An area that is consistently 55 - 60°F is good.

Watering: As with most plants brought in to overwinter, consistent watering is one of the important keys to keeping it alive. Water when the surface is dry, usually once every 2 weeks until the soil is wet and water comes through the drainage hole.

After about an hour, empty the water from the saucer so the roots are not sitting in water. Rosemary will benefit from misting. A tip for watering all indoor plants is to allow tap water to sit in an open container overnight to allow the chlorine to dissipate. 

Air Circulation: Good air circulation can alleviate some problems with mildew and mold. If you have several plants overwintering indoors make sure there is good spacing between them.

ABOUT ROSEMARY

Rosemary is the herb of remembrance. Although today we typically think of it as remembering loved ones that have passed, the Greeks thought it increased memory. Greek scholars were said to wear wreaths of rosemary around their heads when taking exams to help them remember their lessons.

The name rosemary derives from the Latin for dew-"ros"- and sea -"marinus;" thus, dew of the sea. A legend says that the Virgin Mary spread her blue cloak over a white-blossomed rosemary bush when she was resting causing the flowers to turn blue. The shrub then became know as the "Rose of Mary."

You may also be interested in the eBlog post Overwintering Rosemary Outside

~ Carol Kagan, Master Gardener

******

Interested in herbs? Check out my book, Herb Sampler. Want more information on the Herb Sampler? Check out this Blog POST 

Carol Kagan, Master Gardener

Overwintering Rosemary Outside

 

After posting a Tuesday Trivia about Rosemary on the Penn State Extension Master Gardener Facebook page, member Jai Cee asked about overwintering Rosemary in Centre Co., PA. Here's some information I copied from a previous Master Gardener post.

Overwintering Rosemary Outside

Currently there are five rosemary varieties that are likely to survive our most severe winters: 'Arp,' ' Hill Hardy,'   'Salem', 'Nancy Howard,' and 'Dutch Mill’. Not all plants listed as hardy will be so for every gardener in the same area. While the rosemary variety 'Miss Jessopp's Upright' has been sold as winter hardy up into south central Pennsylvania, it is inconsistent in its hardiness, dying off in areas as far south as Virginia and yet overwintering in some lower Pennsylvania counties.

Rosemary should be planted before June 1 to allow it to get well established and regular care will result in a healthy plant. Plants sited in sheltered areas, such as near a wall or fence, will get some protection from wind damage and dehydration. Rosemary needs good soil drainage and benefits from southern exposure for the most winter sunlight.

Some Winterizing Tips

Even for winter hardy plants, gardeners can protect against the cold.

In addition to cutting weak, dead and damaged branches, trim any branches that are too low. Fall is not the time to do pruning on rosemary as it will promote new growth that is highly susceptible to frost. Give the plant a deep watering and mulch around the bottom of the plant.

Depending on your site, a small wind break made with tomato stakes and cloth or burlap stapled to them can help.

This is not rosemary but an example of protection.

In our area, rosemary plants need protection from frost, snow and ice as well as wind during the winter. A good way to provide this is to cover or wrap the plants. To provide plant and branch support from heavy snow and ice, wrap the plant with burlap.

Start at the bottom and gently pull the branches loosely together. Overlap the burlap as you wrap to the top, leaving enough burlap to fold over and clip. This will give keep the branches from extending out and collecting the weight of snow and ice on them. Wrap twine loosely around the burlap to secure it. This also reduces light to the plant.

Alternately, put a tomato cage around a plant, or stakes, and wrap them with burlap, leaving extra at the top. The cage or stakes need to be in place before a hard freeze. Fill the inside space loosely with leaves and clip the burlap closed at the top. The leaves help insulate a plant.

You may also be interested in the eBlog post Rosemary Spending the Winter Inside

~ Carol Kagan, Master Gardener

******

Interested in herbs? Check out my book, Herb Sampler. Want more information on the Herb Sampler? Check out this Blog POST 

Winter Care Tips for Indoors Plants

 

Rosemary in window-Turn 1/4 every few days to keep growth even (B.Petrucci)

It's January - midwinter here - and most plant puttering is done on and around those poor souls inside the house.

When my family, friends and neighbors ask me (the Master Gardener) about caring for their houseplants I try to answer without laughing.

Outside my door, plants thrive; however, my house is just hospice care for houseplants. I am just about to lose an aloe plant that has lasted since 2009. I'm really, really sure it needs to be repotted.

For the tender perennials I bring inside in winter, my rosemary particularly, my goal is to keep it alive until I can put it back outside.

From Master Gardeners I have learned a few key things, so here is my quick tip list followed by a number of great resource sites. It is important to check the needs of each plant since they can vary greatly.

1. Be sure the plant is potted in the right size container (with a drainage hole) and right potting soil.
If you are digging it up and dragging it in from the outdoors then potting it up, don't use garden soil. It's too heavy.

2- Water only as needed when the soil is dry.
Water from the top until water comes out the drainage hole (You do have a drainage hole, right?) into the saucer. About two hours later, drain any excess water from the saucer. Don't allow the roots to stand in water. If you don't see drainage but have watered well, check for a clog in the hole and clear it. Inconsistent watering is one of the primary reasons for plant loss.

3- Use room temperature water.
Leave tap water out overnight, uncapped or uncovered, to allow the chlorine and fluorine added to city water to dissipate. Although these probably don't harm plants, you want the water to be at room temperature anyway. Rainwater, snow melt and well water are ok. Don't use water run through water softeners.

4- Light should be appropriate for the plant.
Each plant is different - flowering plants need moderate light, some foliage plants do well in low-light areas but other need more. Rotate plants near windows to allow for even growth. Improper lighting is only secondary to poor watering practices for plant failure. See below about light level definitions.

5- Humidity indoors in the winter is low.
Use a water-tight tray with constantly moist sand or gravel in it under the plants. Do not put the pot IN the tray. Put the pot with saucer ON the tray. Misting leaves daily can help with low humidity but some plants such as orchids or gardenias need special care. Check sources for help on these.
Be especially mindful of tender perennials that you have brought in from outdoors to overwinter in areas where you may still be running dehumidifiers, such as basements or lighted storage areas.

6- Temperature needs of different plants vary.
Be careful putting plants near windows for the light. These areas might be cold spots or hot spots, especially if they are sited near radiator or heat sources. Although some indoor plants will tolerate cooler rooms, most like temperatures 65° – 75°F.

7- Fertilizer once a month with water-soluble complete fertilizers.
For most plants winter is not a growth period so fertilize lightly. For tender perennials brought indoors, do not prune as this may stimulate growth. Typically, plants in our area use winter (shorter days, longer nights) to go dormant so anticipate slower growth and let the plant rest up. If you have indoor flowering houseplants, check the needs for each individual type. Some may need a healthier dose of fertilizer.

Indoor Light Definitions

Here is a good list of indoor light definitions I found that coincide with information gleaned from different Extension sources. I have not reformatted the information provided by Will Creed (http://en.allexperts.com/q/House-Plants-721/Light-level-definitions.htm).

“The low/medium/high categories are somewhat vague and overlap considerably, so there is no rigid definition for them. Below is my [Will Creed] best effort to bring some clarity to these terms.

High light plants must have some direct sunlight for at least several hours per day and bright indirect light for the rest of the day. South and west facing windows are the best locations for these plants.

Medium light plants must have bright indirect light all day long and can often tolerate a couple of hours of direct sunlight. East and north facing windows are the favored locations for these plants.

Low light plants must be protected from direct sunlight at all times. They thrive in bright indirect light, but will often tolerate minimum light levels. These plants prefer locations close to a north window or away from an east, west, or south facing window where they are protected from the direct rays of the sun.”

~ Carol Kagan, Master Gardener