A Southern Willamette Valley Seeding Calendar

Including season-extension using propagation greenhouses or hotframes

v. 2.12 February 8, 2008



marks highly recommended seeding times.
marks use of supplementary heat.


Alliums Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Onions [1]       x                                    
Leeks [2]       x                                    
Scallions/Green Onions       x                                    
Shallots [3]       x                                    
Garlic [4]   x                                 x      
Legumes Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Peas [5]     x                                      
Green Beans [6]                     x                      
Dry Beans [7]                 x                          
Favas [8]                                     x      
Brassicas [9] Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Broccoli [10]                                            
Cauliflower [11]                                            
Brussels sprouts                                            
Kale [12]         x             x                    
Collards [13]         x             x                    
Radish [14]                                            
Pac Choi [15]                                            
Kohlrabi [16]                                            
Turnips [17]                                            
Rutabagas/Swedes [18]                                            
Arugula [19]                                            
Asian Greens and Mustards [20]                                            
Winter Brassicas [21]                                            
Cucurbits [22] Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Summer Squash [23]               x                            
Winter Squash [24]               x                            
Cucumbers [25]               x                            
Pumpkins [26]               x                            
Melons/Watermelons [27]               x                            
Gourds [28]               x                            
Nightshades [29] Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Eggplants [30]       H x                                  
Peppers [31]       H x                                  
Tomatoes [32]         x                                  
Potatoes [33]                                            
Umbels Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Carrots [34]                                            
Parsley [35]                                            
Dill [36]                                            
Celery [37]                                            
Parsnip [38]                                            
Composites Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Lettuce [39]                                            
Chenopods Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Beets [40]         x                                  
Spinach [41]                                            
Chard [42]                                            
Others Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov
Sweet corn [43]                                            
Flour, dent & flint corns [44]                                            
Basil [45]                                            

Don't start storage onions past the end of March. They require time to mature and then dry down.
Transition to winter varieties in April.
Shallots can store in your pantry until June, in other words, much longer than the most long-storing storage onions. This characteristic lends them a defining presence in the gardens of people serious about feeding themselves year round. As with onions, late Feb marks an optimal time to sow, late enough to enjoy more momentum than earlier sowings, but early enough to mature and cure in the heat of mid- to late-summer. Sown as bulbs in Oct/Nov, as distinct from seed, the plants will put on a flush of growth in the spring when they can be harvested as 'green shallots' or left in the ground to grow to full maturity and harvest in July. Fall sowings allow time for next year's winter brassicas to occupy the same beds. You can grab the mature bulbs from a summer/fall harvest and stick them right back in the ground again. If sowing by bulbs rather than seed, the shallots tend to ahve more cloves within each mature bulb; by seed, each mature bulb tends to be bigger and with fewer clove-divisons.
Conventional wisdom has it that garlic has to go in in October. Garlic is far more forgiving. if you miss your fall sowing, never mind, sow in early spring for very similar results. Some long-experienced growers hereabouts sow only in spring.
By early April, sow enation-resistant varities. Typically direct-seeded in mid-February, you may get an early start by seeding in the greenhouse in late-Jan thru early Feb, then transplanting. If speed to harvest is such a priority, try shorter-season bush varieties. Try sowing peas for fall in the mid-July to mid-August window to harvest in October. Mid-July is optimal because later sowings may well get frozen out - the peas will taste bitter once frozen. The high heat of July is surprisingly not too much of an issue for this cold-loving crop - the small plants don't seem too bothered. By late September, when the plants are sized up and the blossoms are coming on, the temperature has cooled significantly.
Sow successions for a continuous harvest. A final end-July sowing will take you up to frost-time: fresh green beans on vigorous plants are quite the treat when everything else summery in the garden is yellowing and slowing down. The plants from a late-July sowing won't be as productive, but they will be the last 'pick-mes' available until the frost comes in. Do not overwater newly direct-sown beans - they will have a tendency to rot.
Dry beans are direct sown, if really warm, in late April, but usually in late May. Early to mid-May is ideal. Plant beans of different maturity lengths in mid-May. Past late May, go with a buckskin.
Sown in the spring rather than fall, the beans will mature 3-4 weeks later for eating. Can be used as a super-quick early-spring-sown cover crop, turned in, and breaking down very quickly indeed, before a late-spring, early-summer food crop is planted in the same bed. If sowing favas in the fall, try planting into a thick leaf mulch - the favas will come through and your soil will be sheltered from the beating winter rains during the several months that the favas are too small to offer much protection.
It is especially important to keep the momentum flowing smoothly for the ‘heading brassicas’ such as cauliflower and broccoli – one reason why growing these plants successfully can prove challenging for the inexperienced gardener. If your transplants get stressed at any stage, cauliflower especially, compost them – they are likely to amount to little. Eratic weather conditions in the spring can confuse the heading timing of thse plants, too – another good reason to make succession sowings - every two weeks if you have the ground to put them into. Some experienced gardeners avoid spring sowings of broccoli altogether, given its all-too common tendency to head up while still a very small plant, at this time of year. Cauliflower, another 'troublesome customer' for many is more predictable with a later sowing in mid-March. Choose varieties specific to the seasons. With the transition to fall and winter varieties sown in May and June, reckon on 2-3 further rounds of sowing.
By all means, give this crop a go, but many experienced hands - who have a focus on predictable productivity - find spring broccolis' performance too erratic to justify the space. So very often the plants, confused by changeable spring conditions, will mature a very small head long before the plants have sized up. Home gardeners, of course, may be content to embrace reduced yields, just to have broccoli around. One tack: consider sowing in April or May, somewhere a little cooler, say behind unpruned raspberries, or in the tree -shade of an afternoon sun. Broccoli excels as a fall crop, however, sown in June through mid-July, transplanted by end-August, producing huge heads with lots of side-shoot action, through to December and, of course, it will be sweetened somewhat by the cooler weather where spring-sown broccoli, growing into warming temperatures, is not. Fall broccolis seem only ever to be unreliable if they are planted out a little early and then we have hot temperatures in September, say in the 90s, when aphids will hit the stressed plants hard. Then, of course, there are the Sprouting or Overwintering Broccolis, very different varieties, sown in June, for cropping December thru May.
Cauliflower, like broccoli, can be a challenge raised into the spring. Some varieties are very fast, producing smaller heads - so plant them more densely. Where cauliflower really comes into its own is as an overwintered crop, producing huge heads from the new year through to late Spring. Overwitnering varietal choices, offering a broad array of maturities, are available, though they can be difficult to source. Where going with a single variety, Maystar impresses.
Grows year round but consider growing it for harvest only in the fall and winter when it tastes much better in the winter when sweetened by the cold and is also not so aphid prone. See winter crop guide.
Grows year round but tastes much better in the winter when sweetened by the cold.
At only 30 days to maturity, this crop affords much speed and flexibility. Sow as often as your palate wishes. Sown in May through early July, the results will be very spicy and may also bolt quickly. Perhaps find a cooler spot in the garden for them if sowing then.
Very fast out of the blocks in early Spring, though it does have a tendency to bolt once the summer heat comes on, but experiment with different varieties. A superb fall crop. Under cover - the plant is extremely vulnerable to hail, for example - bok choi is, one of the few crops it is possible to grow happily in the ground, year-round.
A crop many people don't know how to eat but, among afficionados, commonly regarded as 'the candy of the garden'. An early February seeding, transplanted in mid-March, will be ready mid-April through the beginning of May. The leaves can be harvested as 'kale' when the plant is pulled - tending to be sweeter and more tender than kales harvested at that time of year. Of varieties readily available locally, White Vienna is fast, sweet and crisp; Superschmeltz juicy but a little slower, and Purple Vienna has the most flavor but is also the most savory.
Can be direct sown outside in April. Many people grow them for greens instead of turnips. This crop really comes into its own as a winter crop, overwintering outside, well.
A great fall crop, sweeter than carrots, especially after the first frost comes in.
Aurgula is easy to grow and consistently, a very firm favorite among those eating fresh greens in our bioregion. It is very fast, but will bolt quicker than other crops, too. Succession sowing helps. Fall sown, the crops will weather the elements admirably outside through until the end of November when they will begin to look ragged. Greenhoused, they will hold beautifully until February when they are among the first plants to run to seed.
Mizuna and mustards re-cut very well. Plant them a couple of times for a continual harvest. Mustards are fast, but do have a tendency to bolt into summer heat, when they are also exceptionally spicy. Perhaps sow no later than March, before picking up again in the fall for sowing as a fall and winter crop when they really come into their own. Purple Wave mustard, an intense -wasabi-tastelike mustard is a vigorous year round presence in gardens, especially where it is allowed to self-seed, when it will simply estabish itself as a regular presence. Hot and spicy whenever in the year you eat it.
Transplanting dates more critical than seeding dates. A couple of weeks lost into the declining light levels of early fall can make all the difference between a winter garden that will feed you well and one which won't. Late July and very early August the key transplant window.
Cucurbits grow very fast in pots – one month from seed to transplant. Contrary to rumor, they are not difficult to transplant, unless they tend toward the root bound, in which case compost them.  By all means try an early sowing but, if not transplanting into green/hot houses, then seeding in mid-April is optimal, otherwise you will likely have plants ready before temperatures are warm enough to transplant outside. Avoid the use of black plastic on the ground. Non-organic oogies aside, the tendency of vining squash to root at nodes is compromised and the plants are not as happy.
A significant challenge for organic growers hereabouts is the arrival of the cucumber beetle in early summer, typically just as we are transplanting out our major cucurbits. The use of remay to cover the transplants is very common. One approach: cover the plants with remay, but leave enough looseness for the plants to grow for 3 weeks. The protection from the cucumber beetles and the additional heat provided by the remay will result in plants sizing up very quickly so that when you remove the remay three weeks after transplanting, summer squash will be producing within 3 or so days.
Winter squash, a critical component of a sustainable year-round diet - varieties will store up to 8 months and you will be eating it as zukes come on the following year. Winter squash has a longish cycle to maturity that makes it a marginal crop hereabouts. The head-start provided by growing up transplants in a greenhouse consistently makes the difference between a crop that fully matures and one which doesn’t. If seeding past June 1, seed a very early variety - these tend to be smaller fruited. Recently, commercially available Delicata seed has proven difficult to germinate without rotting. You may need to re-sow.
Cukes can be direct sown in a greenhosue in mid-March. Marketmore and Telegraph are two predictable, well-performing OP varieties.
Seeding-wise, reat pumpkins like winer squash. If you miss your earlier seeding window and are forced to seed late, direct seed through June but choose smaller fruited, faster varieties and cover with remay to accelerate early growth.
These are two of the most consistently hallenging crops for us to grow locally - the problem is compounded by the fact that there are few solid OP lines that do well hereabouts. Don’t trust seed packet maturity dates for watermelons unless you are using heat-enhancing aids such as lots of non-organic black plastic.
Most gourds have a difficult time maturing seed hereabouts
Eggplants and peppers are the two summer crops that gardeners find most challenging to ‘size up’ – hence these corps respond well to season-extension tools such as supplementary heat in February. Others are happy to seed in mid- to late-March, with much less in the way of overhead, but expect smaller plants.
A crop that responds excellently to being grown in a greenhouse. Transplanted outside, yields will be later, smaller and, occasionally, marginal.
A heat-loving crop that responds well to greenhouse growing in the summer. Grown outside, yields will be acceptable, though harvesting peppers whle they are green, before they color up, will definitely produce more. Getting colored peppers to produce outside, in quantity, is a challenge. Picking consistently and regularly appears to keep plants in production mode. Cal Wonder and Gourmet sweet-  and Aci Sivri hot-peppers are readily-available OP peppers that do well here. Golden Bell, as smaller pepper, may color up where others do not.

March is perhaps the optimal month for seeding tomatoes, giving you two months to size up a plant while maintaining impetus. Jan/Feb sowings are possible, but you will need to keep potting up and protecting the plant, and/or have a greenhouse to plant them into. Too-early seeded tomatoes tend to become leggy and are more susceptible to disease. Tomatoes are, however, very forgiving plants and will recover suprisingly well from ill-treatment at the hands of inexperienced or careless gardeners. You can, if needed, seed as late as end May and plant out in late July - you will be harvesting green tomatoes just before the frost or rains come in. Take the tomatoes, remove the green sepals (which will puncture skins) and fill banana-boxes half-full, and store them in a 50 - 60 degree room. Look through the boxes once a week to remove ripened/damaged toms: the tomaotes will last you easily through Xmas and perhaps into February. Paste tomatoes store the best of any - thick-skinned and less juicy, they have less of a tendency to suffer bruising or rot. Advice on varietal choice is plentiful. For paste toms, Amish Paste is prolific. Oregon Star is huge and dense.

if soils aren’t dry enough, potatoes will rot if planted too early. Some gardeners with fluffy soils take volunteer potatoes from the compost pile in early Spring and transplant them into beds covered by cloches. Open the cloche on hot days. Eat potatotes by May/early June. March 15, St. Patrick's Day, is a traditional potato planting day. Uncovered early-sown potato plants will get their foliage knockced back by frosts but will typically bounce back. However, cloched potatoes will do better. Later-seeded potaotoes appear more likely to succumb to the ravages of flea beetle. Plant for large, reliable storage potatoes for the winter in May - you will be pulling them in September rather than August. However, adventurous souls can succession sow July through the end of August. Most potatoes are 55-70 day maturities - and Aug, Sept and half of October amounts to 75 days, long enough. If we have an unexpectedly early frost in mid-September from an August planting, you will still have lots of baby potatoes. I'm told that potatoes harvested later, store longer through the winter. Don't overwater potatoes - they will wilt.
Experts will tell you this impossible or unwise, but I know of one gardener locally who has successfully grown potatoes in the same patch for 12 years - with volunteers providing each year's new crop.
March sowings will need to be done in the greenhouse. April sowings will benefit from a cloche. Switch to varieties you hope to overwinter in mid-June to mid-July. Either either let the carrots remain in the ground or harvest in December and put in sealed bags in the fridge - where they will keep sweet for as along as a year. Left in the ground, the carrots have a tendency to decline through the rigors of early spring.

Parsley is slow-growing. It will spend 2 months in a pot prior to transplanting and won't exactly jump once it is in the ground.
This plant is referred to as "dill weed" for a reason. Where possible, let the plant reseed. Starts tend to be spindly and have a tendency to bolt.
Seed fall varieties first week in May. The plant is hardy and will grow back from a freeze, but some gardeners will pull the plant in October to allay concerns about encouraging celery blight in the garden.

The germ rate may be as low as 60% even in good times: direct sow thickly and thin to 4 fingerwidths. Seed sown in cool conditions may take as long as 3 weeks to germ - worrying novice or impatient gardeners. Sown later, covered with shade cloth, they willg germ in a week. If sown in June, the plants will tend to grow to about 1 1/2" to 2 1/2" then wait, until the weather cools in late August when they will take off. May/June sowings for the winter perhaps optimal, but a later sowing in July will produce smaller plants that are easier to dig - an important consideration in our waterlogged winter soils. Either harvest and put in sealed bags in the fridge in October, or leave them in the ground through March. Once new growth kicks in in the spring, the roots have a tendency to get woody.
Seed every two weeks for a continuous harvest then, toward the end of the warm season cycle, as temperatures and light levels decline, sow more numbers - the slowing growth and colder temperatures will keep them harvestable longer. Try seeding mid- to end-September in trays, then keeping them outside, to transplant into a greenhouse in February - by mid-March you will have large, healthy heads.
Sow in the ground in early March. If sowing in cells in a greenhouse for transplant - perfectly doable - you can sow earlier. Try seeding them in flats through the end of September, then transplanting into a greenhouse in February to harvest in mid- to late-April.

A particularly cold-tolerant germinator which comes up better than lettuce and Brassicas in early spring. Switch to summer varieties of spinach at the beginning of May.
May-June sowings of chard are possible, but chard doesn’t like the summer heat. Make a point of having sized-up chard going into a winter - chard fills the end of spring hunger gap where all the Brassicas have run. Fordhook Giant is hardier outside than other chards through winters.
Sweet corn can be started in cells in mid-April for transplanting out in mid-May. It is very fast in trays (3-4 weeks) so transplant out quickly. Earlier-seeded corn has a tendency to bolt and produce lower yields. If direct seeding, mid-May is generally the earliest. A very late crop sowed end-July is doable but risky.
Carol Deppe tells me: “The conventional wisdom about field corns being hardier than sweet corns and flints being hardier than anything is true only statistically. What matters more is the specific variety.  There’s been a lot of work in the last couple decades on hardiness in sweet corns. Many varieties of corn including sweet corns have frost hardiness when they are small seedlings. But not when they are bigger plants. Also, they all require some warmth to germinate.  And some grow better in cool weather than others.  People seem to mean mostly survival of freezes when they say “hardy.” But beyond that, some corn varieties grow pretty well while the weather is still cool.  Others expect actual warmth, and actual warmth tends not to happen in Western Oregon until actual summer. 

“Here in Willamette Valley of Oregon hardier corn varieties, including sweet corns of hardier varieties can be direct-seeded as early as the last week in April with good results.  I like to plant a first planting from the last week in April through the first week in May, when possible, given appropriate weather.  That means weather that has dried out well enough to till/dig the planting area twice, and the weather report for the few days after the planting is predicted to be warm, not cold.”

“I’ve planted corn as early as April 1 with presoaked seed. (Presoaked indoors to break dormancy and give the seed enough warmth to start sprouting.)  However, there is no particular advantage to planting so early in most years. The seedlings of most varieties will tolerate mild freezes.  But there isn’t enough warmth for the plants to grow well until the last half of April. At best, the seedlings sit there waiting for better weather.  At worst, they get root rot or get eaten by sow bugs or slugs or pulled up by birds. A corn seedling a couple of inches high is a very vulnerable thing. Every crow and blue jay in the world seems to know there is a delicious kernel that can be had if they pull up the plant.  On such a tiny seedling, a few chomps from even a small slug decapitates the entire plantling. It generally works much better to plant later so that there is enough warmth so that the corn germinates and shoots through that most vulnerable stage in just a few days. Also, if you plant a month earlier than good corn weather, even if the seedlings all survive, you have to weed for an extra unnecessary month.”

So I take May 1 plus or minus a week as the direct seeding target date for the earliest planting of most corn varieties (dry seed), including the hardier sweet corn varieties.  When we have wet springs, there may be little opportunity to till and thus to plant corn until much later.  Planting later in May gives corn that matures only slightly later. If you plant May 1 and June 1, for example, the June planting may mature only a couple weeks later than the May planting, not a full month later.”

I think most people’s first corn planting (from a direct seeding) in most parts of the temperate world will be towards the end of the part of spring that still has occasional freezes.  So here, for example, we still get occasional freezes the first week of May or so, but not usually beyond mid-May.  And it works to plant the first corn planting about a week before May 1, but not much more. If you wait until you expect no more frosts in your area, that’s a fine time to plant corn, but the first planting could have been back when you still had risk of occasional light freezes.”
I think of the direct seeding schedule in spring thus: There is pea and fava bean planting time.  Then time to plant cool-weather spring greens.  Then it’s time to plant corn.  Then squash. Then to transplant tomatoes and plant beans.  The pea/fava planting time still has hard freezes and is mostly cold weather, but with occasional cool periods.  Peas and favas can grow when the temperature is much above freezing. The cool-weather greens can tolerate freezes, grow well in cool weather, and have photoperiod requirements that fit this schedule. The corn-planting time still can have occasional light freezes. But it has considerably warmer weather than earlier in the season. Corn needs warmer weather to make good growth than peas or favas do, so there is little point to killing yourself trying to get it in earlier than this.  The squash, tomatoes and beans are normally killed by frost, and thus are put in after most danger of frost is past.”
Basil is a slow-growing start taking about 6-8 weeks from seed to transplant. It does not like to be rootbound. A few plants go a long way. Most poorly-performing basil has been planted out too early.