Tuesday, September 11, 2007

Endless Summer... Bring the garden indoors!

Fall is definitely in the air on the Prairies: trees have started to turn, the marigolds and perennial grasses have taken on their characteristic autumn intensity, and the winds have started to blow cool nights in on a regular basis. At Sage Garden Herbs, people are starting to ask about bringing their herb gardens indoors. Truth be told, the ideal time to start bringing herbs indoors is past (late August/Labour Day weekend) - but no matter, it can still be done!

The most important question people have is, "how do I avoid indoor pest problems?" The good news: simply washing your plants with a garden hose is one of the most effective, safe, and accessible tools in preventative pest control (your goal is really to prevent pests, not treat them once they occur). This should first be done outdoors, where you can really spray all parts of the plant, including undersides of leaves, stems, and woody bark. Most pests will be hiding out on the underside of upper growth. The follow-up requires prunning away top stems and leaves; this will encourage fresh new growth indoors, and physically remove the most likely pest-harbouring leaves. Woody plants like rosemary should be pruned just on new, flexible growth. Leafy plants such as mint or Vietnamese coriander can (should) be cut back almost all they way to the base - this will cause vigorous, healthy, and clean new growth indoors.

Once plants have been moved indoors, they should be rinsed under fast flowing fresh water (big sink, or shower for larger plans) once every couple of weeks. This will keep your plants very happy indoors. If you want to spray your plants with an ORGANIC insecticide we recommend Neem Oil, which is inexpensive ($8.95 for a 125ml concentrate bottle @ Sage Garden Herbs) and actually has preventative action rather than just controling insects in the moment.

The second biggest concern involves choosing appropriate varieties to grow indoors. This is a critical issue!

The best herbs to grow indoors are evergreen perennials from the warmest climates (zones 10-tropical). Some wonderful examples include allspice (if you haven't smelled fresh Allspice, you are invited to scratch and sniff our beatutiful tree at the greenhouse - it is amazing!), Cuban oregano, broadleaf thyme, gingers, Night Scented Jasmine, and tea tree. These plants thrive on year round warmth, and generally do not mind the decreased light levels of winter. Water and fertilize these types of indoor plants about half as often as you would in summer.

Many of the familar culinary herbs come from the moderate climates of Southern Europe (zones 6-9). These plants require lots of light, but cool night temperatures. Some examples include Rosemary, Sage, Thyme, Lavender, Bay Leaf, and Myrtle. These varietites can be long lived and wonderful indoors through winter, but require the coolest night temperatures you can provide. Ideal locations include cool sunrooms, large windows (bay window), or patio doors. In our greenhouses, we allow these plants to get close to freezing; at home this is likely not possible, but at all costs avoid placing these plants near heat vents or radiators. These varieties are used to growing in conditions considerably more humid than a home heated with forced air in winter; this issue can be helped by placing the pots on a pebble tray (rocks placed on a saucer), a common technique used by orchid growers. Water and fertilize (with an organic plant food, otherwise salts will build up in the soil overwinter) these types of herbs about half as much as you would in summer.

Hardier perennials (zones 1-5) are not easily wintered indoors unless you have a cool greenhouse or can accept that they will be mostly dormant through the winter. These types of plants have developed strategies for lasting through cold winters by storing energy in their roots, a process that is triggered by cool nights and diminishing daylight in late summer/fall. Even grow lights are unlikely to coax these types of herbs into active growth for winter, with the exception of evergreen hardy perennials such as winter savory or hardy thymes.

Finally, I must raise the frustrating reality that basil, cilantro, dill, and other annual herbs are not suitable for bringing indoors. These plants are designed by nature to live for a single season, and stop growing once they have set seed. Although pinching flowers will prolong the plant's lifespan, most annual herbs cannot thrive once fall daylight hours have set in. The good news: Annual herbs can thrive under a simple fluorescent growlight! Indeed, some of our most content customers are those who set up an inexpensive light, allowing them to enjoy fresh herbs of all types even as the snow flies across the Prairie. We offer an excellent, affordable ($35.00) grow light called a T5, which has an ultra low power consumption ballast, full spectrum bulb, and easily mounts in the kitchen. Annual herbs should be started fresh from seed under lights, rather than brought inside. Annuals grown under lights should be watered and fertilized as if it were summer.

Indoor herbs thrive in 6 inch and larger containers, and benefit from a potting soil with compost incorporated into it. As an observation, anything that can be done at the outset to reduce care requirements greatly contributes to a successful indoor gardening project (think about how busy we all are during the holiday season, or how reliable your waterer will be when you are away on a winter vacation). Larger pots, and compost based soils reduce watering and lessen the need to be right on with fertilizing.

Well, I hope these ideas address the questions you might be having about bringing your herb garden indoors. If you have additional questions, or would like to post a comment, please do so. You can always drop by the greenhouse and see some of the fantastic varieties that can thrive indoors - and talk over your indoor gardening plans (PS. We also have lots of hardy perennials on sale, which can be planted out right into early October).

On behalf of Ev, and the staff at Sage Garden Herbs, thanks for checking out our first post!

Dave, SGH


Cindy said...

I am amazed no one has commented on this blog yet!
This has given me wonderful information about the herbs that I've brought into my house and put on my bay window sill in the kitchen. I started a little late this year, and this is such good advice! Thank you! I'm definitely bookmarking your site!

Jeff said...

Hi, I was looking for tips on overwintering Bay Leave shrub/tree. Mine is about 10 years old and last year I almost lost it with many leaves drying out mostly as a result of insects (scales) on the underside of leaves and soft stems. I understand neem oil is the best solution to this problem. Can you speak to it soon?

I found this blog very helpful so far.


Sage Garden Herbs said...

Hi Jeff,

Your question is a really important one for northern gardeners wanting to maintain bay tree indoors. Scale insects are the number one issue that comes up. Neem oil is very effective at killing scale, but really the solution has three parts:

1) wipe obvious scale insects away with a cotton ball and rubbing alcohol
2) Spray all leaf surfaces and stems with a good quality neem oil (some brands are much better at dissolving in water compared to others)
3) remove top 1/2 of soil around perimeter of the pot, wipe inside and outside perimeter with rubbing alcohol, and replace soil with fresh potting mix.
Respraying with neem oil every couple of months, as well as an annual check for outbreaks of scale should keep your plant happy for years.

One other note; tip burn on bay leaves is usually a sign of underwatering. This is tricky, because bay does not need a ton of water indoors overwinter, but if it gets just a little too dry the leaves will show signs of stress quickly. If left for a week or so too long, it may stress the plant to the point of dying.

Finally, bay has big, thick leaves and gets dusty quickly indoors - like all indoor plants, it benefits from regular rinsing under fast flowing fresh water, or at least a good wipe down to remove the dust.

Dave, SGH.