Siberian Iris

Siberian iris, are one of the most carefree, taller garden flowers. Given proper spacing, a 6" pot of these beauties can grow into a plant 1-2' across in a couple of years. "sibs" as they are commonly called, bloom right after the tall bearded iris. Bloom period lasts about 1 month. Their color range is white, yellow, pink, blues & purples. Sibs have thin, but sturdy grassy foliage, adding that 'swish' to the garden on breezy days. Unlike regular iris, they are seldom bothered by iris borer.

Above is 'White Swirl.' This iris has a very long bloom period. All sibs will last cut in a vase one week or more, with the water changed daily. Clumps of sibs should be divided every 3-5 years. The more space they start with, the less frequent you have to divide. Keep in mind, the longer you wait to divide, the harder it is to dig that plant up.

"Pink Haze" is above. So pretty. Even after it rains, these flowers hold up well.

Plant info:

height: 24-40"

locate: in full sun to 1/2 shade

water: prefers moist location, but once established will tolerate drought

insect & disease: nothing major, very carefree

fertilizer: average to none in healthy soil

hardiness: some of the toughest plants around, maybe winter mulch 1st winter

fall care: cut back tops after hard frost

Earthworks will have all of these and more available in pots this spring and lots in the field for cutting.

Tomato Plant issues

I know you aren't really thinking about growing plants in December. However....during the off season is when I have more time to blog and explain gardening tips & issues. I will not be teaching gardening classes this coming spring, possibly again in 2013, so listen up ! =0 Both photos here are of late blight on tomato fruit & foliage. There are many different diseases-blights-mildews that garden plants are susceptible to, but the steps for cure & prevention are basically the same.

How do problems spread? They all have their own mode of travel. Some spores like that of late blight travel on wind, some live in the soil and travel by water after it rains, some issues like 'potato scab' are soil borne diseases which can be initiated by horse manure. Once you have it, it NEVER goes away.

How can we prevent some of these problems?

-start with healthy plants

-choose resistant varieties

-allow correct spacing for air flow, 3-4 sq. ft. per tomato plant

-place straw mulch around the bottom to prevent moisture loss, and reduce splash back on

plants from rain & hand watering

-always water at the base of the plant, keeping foliage dry when possible

-water in the morning if you have a choice, this allows the plant to dry off better, vs. staying

wet through the cooler nights

-never use sprinklers, they waste water and are perfect disease spreaders

-water only 2 times weekly, applying 1-2" total per week, minus rain

-do not water daily!

-soon after planting (within days) start a regular spray program w/a fungicide. REGULAR &

TIMELY applications will likely prevent most of your plant issues. Fungicides are only a

preventitive....once you have problems it's too late. You can find fungicides at the garden

centers.

-crop rotation is not that effective for home gardeners. Unless you garden is 1/4 acre, you are

still dealing with a basic monoculture

-remove diseased fruits & leaves as you notice them, careful not touch good leaves with your

hands until washing or you will be spreading it around. When 30% or more of the plant is

affected, pull up and get in the trash.

-NEVER till until your garden debris or compost veggie plants. The average compost heap is a brew pot of disease & insect eggs just waiting to re-infect your garden in the spring. Burn or disppose in the trash. Tilling under just helps to 'winter' it over until you till it up again in the spring, and the cycle begins.... You will often at this blog, read about NOT composting. I find it is the hardest point to hammer home to gardeners, because that is what grandma did, and they have done for years! It is the single biggest correction you can likely make to help improve your bottom line in the garden, and it's easy to correct. I am not against 'correctly' running a compost heap that will heat up in 2 weeks and break down. The problem is the correct layering & percentages of green & brown materials, the regular turning & watering. It is really simple, but seldom happens correctly and instead becomes a toxic heap. If all this sounds like too much work, just stop the farm or market next year and get our tomatoes!

Still time to cover plants if needed.

Who needs to get covered in the winter and why do we do it? If you started with plants that are for zone 4 or colder regions like zone 3, and planted them timely....they should not need to be covered. A zone 4 plant should be able to withstand our winter climate as it is. Trouble is....the same plant can be found in multiple sources that will all have a different zone listed. Zone 5 is south of us, starting mid Iowa. Zone 3 is north, starting by the metro area. If I find conflicting zones listed, I check about 3-5 sources on line, looking for an information site, not a sales site. In theory.....zone 3 plants here should never need mulching and zone 5 will always - and still they may not make it-wrong plant for our climate. There is our course always exceptions. Case in point; my Pink Delight Buddleias rated as zone 6 (think southern Missouri), that not only they survived 2 winters here, but survived in 2 gallon pots! Amazing.
There are different reasons to 'winter mulch' plants.
Plants that were installed late in the season: 6" of mulching these will help to insulate the surrounding soil, keeping it warmer longer, to allow a little more time for root growth. This will be especially helpful to plants that you perhaps moved or divided too late or too small in the season.
Plants with shallow root systems like strawberry & mums: mulching helps these types when spring rolls around. The freezing & thawing that we have in the spring, warm days & freezing nights, pushes the plants out of the ground - a process called 'heaving.' The mulch material helps to keep the temperature directly near the plant more even until spring is really here.
Plants the can be semi-evergreen like some types of daylilies, ground covers, geranium etc: winter mulch helps to keep these types from drying winter winds if no snow cover is present.
Another good reason to cut back in fall - no foliage to dry out.
Mulch does not keep plants from freezing, most years the ground freezes several feet deep. But thick mulch 6-8," allows gardeners to manipulate the area just enough to help our plants along.
Mulch should be materials that drain & dry quickly like straw, hay, chopped corn stalks or pine needles. Leaves stay wet and compact. If you must use leaves, a least put a thin layer of 2" of the other materials first, so the leaves don't have direct contact.
It's not too late to cover plants and we can't always count on snow to 'cover' them for us. And yes, I would still give the evergreens and perennials a shot of water, you'll thank me in the spring!