Q & A: Flowers

dahliasGot a gardening question? Ask Susan! What follows are reader questions. Each time a new one comes in, I’ll add it to the top. To ask a question, drop me a note at Susan@susansinthegarden.com.

 

 
Q: I meant to ask you how your winter-sown plants did this year (that you did a video about in January)? JA

A: Overall, the winter-sown seedlings did quite well. I think one of the main reasons I like the winter sowing method is because I can start
additional seeds without taking up precious space underneath our grow
lights. The only seeds that didn’t germinate (no idea why!) were the white
strawflowers. Maybe those didn’t care for that method? But the rest
germinated really well. The plants that did well were the ‘Stuttgarter’ onion seeds, love in a
mist, milkweed and Queen Anne’s Lace ‘Dara’. Since we really tend to focus most of our seed-starting time and
resources on edible crops, that’s why I mostly started flower seeds with  the winter sowing method. I intend to use that method again in Jan. or Feb.

Q: I’ve been meaning to ask you if I need to feed my starts with a fertilizer.   I’ve planted them with Johnnys seed starting mix, and some have been in several weeks, but aren’t very big. SD

A: I definitely recommend feeding your plant starts because once they use up the energy stored in their seeds, they are essentially “running on empty.” I like to use a liquid high-nitrogen fertilizer such as Alaska Fish Fertilizer or another type of seedling booster fertilizer (Espoma has some nice products). When the seedlings are young, it’s best to mix up a weaker fertilizer solution. For example, if the label calls for 1 tbsp. of fertilizer to a gallon of water, I use 1/2 tbsp. to a gallon of water instead. I also fertilize the seedlings when I transplant them out into the garden, and again about 2 weeks later.

Q: I got some lovely tall morning glory (blue) vines going (started from seed) but have had absolutely not blossoms or flowers! My friend hasn’t either. What is going on this summer? Is it because of the heat? Just thought I’d ask. KA
A: Well, that is pretty strange, although it would be easy to attribute the problem to the weather since this has been a very tough growing season. I have morning glories growing on an obelisk in our front flower garden and they have been blooming their little hearts out. I have 2 thoughts: 1) are they growing in a sunny area? They really need a lot of sunshine in order to grow and bloom. 2) have you (or your friend) been feeding the plants with fertilizer that is high in nitrogen (the first number on the label)? Nitrogen promotes leafy green growth but not flowering. It’s best not to fertilize them, but if you were to do that, you’d want a fertilizer that is higher in phosphorus (the middle number).
 

Q: Planted many perennials and in the fall proudly labeled them all with tongue depressors marked with permanent marker Sharpies.  Spring came and there was a surprise.  All my detail about plant ID and date planted were gone.  Faded away.  “Permanent” was not permanent.  Suggestions for plant marking this year? EP

 
A: My guess is that the wood in the tongue depressors was just too porous so it absorbed a lot of moisture. I do hate recommending the use of plastic for markers but those seem to last the longest. Re: the Sharpies, I’ve found that even though they’re advertised as permanent, that doesn’t seem to hold true when it comes to using them outdoors. I’ve had good luck with this type of garden marker pen: https://www.greenhousemegastore.com/containers-trays/labels-supports/garden-marker-pen. I’m also hearing good things about this one: https://www.amleo.com/leonard-long-lasting-nursery-marker-pen/p/HNP8B.
 
Q: I live in zone 5 just north of you in Canada. This week we are going to have very warm weather.  Too warm for tulip planting I’m guessing; about 74° f in the daytime and about 44° f at night. I’ve already purchased my bulbs; 500 of them! They are in my refrigerator but I’m very anxious to get them planted. Can you recommend the warmest outdoor temperature that I can safely plant my tulip bulbs and not lose them?  SG, Canada
 
A: I don’t know when your ground usually freezes but you certainly want to plant your 500 (!!) tulip bulbs before then. I don’t see why you couldn’t start planting them, maybe wait until we’re officially into the month of October but they should be fine.
 

Q: I was hoping you could help me with my roses. I planted them last year and they survived our winter (I live in Hauser, Idaho) and were blooming this spring. Doing well. I wanted healthy plants and decided to step out and use fertilizer. But now I have NO roses. Plants seem to be okay but no blooms. So very disappointed. Help! SJ

 
A: Which type of fertilizer did you use? (she later clarified it was a rose fertilizer) For flowering plants, the middle number in particular (which represents phosphorus) should be the highest. If it’s higher in nitrogen, that would encourage healthy green growth rather than blooming. But, if you did use a fertilizer high in phosphorus, my other thought is that roses are typically transitioning into their second blooming period right now. So perhaps yours will be blooming soon.

Q: Susan, how do you organize your spring/seed starting/planting/etc. I am exhausted and I didn’t get half the flowers planted I wanted to. I still have some outside planting left to do etc.

A: I know what you mean about it being hard to keep track of everything. If you go to my website, you’ll see a printable seed-starting scheduler, which is primarily what I use. I also have vegetable-planting information under the “guides” menu but I haven’t created one for flowers yet.

Q: I have an Orchid that has bloomed three times. Now it has one growth on it with lots of buds. It needs repotting can I do it while its in the blooming stage. I have Orchid potting mix and would like to put it in a larger container. Thank you for your advice. PS

A: It’s best to wait until an orchid has finished blooming before repotting it, so I would wait and enjoy the flowers first!

Q: I believe I saw where you had lavender. Do you cover it during the winter? I have some agricultural fabric I just purchased and was thinking of covering mine but then got to thinking that the weight with the snow on top may damage the plants. This is my first season with lavender (Provence and Grosso). I live in NC and we are expecting a couple of feet of snow this weekend. WHB

A: As long as those two cultivars are hardy for your region, you shouldn’t have to cover them or do anything special. Lavender plants are amazingly resilient.

Q: I planted a trumpet vine 3 years ago. I unfortunately fertilized it in the first year, thinking that it would produce more blooms. Instead I got beautiful, thick green leaves. I have not fertilized it since the first year, but it still has not produced flowers. It is beautiful and has healthy foliage. Will it ever bloom or should I dig it up? PA

A: That’s frustrating about your trumpet vine not blooming yet. It’s true that if you put a nitrogen fertilizer on a plant that needs to bloom, it will encourage more leaves than blooms. As long as it’s in a sunny spot and is getting regular water, it sounds like you’re doing the right things. I did find information online that says a trumpet vine can take up to 5 years to bloom, so I would skip the fertilizer and see what happens in the next year or two.

Q: I don’t understand what half-strength dilution means referring to the fish fertilizer. Could you tell me how much to use per gallon of water? OLR, Spokane

A: When I fertilize young seedlings with fish fertilizer, I like to use it half-strength to avoid burning or overfeeding them. This means using half as much fish fertilizer from what is recommended on the label. So, for example, they recommend 2 tbsp. of fish fertilizer to a gallon of water for vegetables, bedding plants, bulbs and annuals. That means I will use 1 tbsp. of fertilizer to a gallon of water.

Q: Do you grow roses? I have pruned them a little in fall so the snow load won’t break the long stems. I’ve had people here tell me not to prune them before winter because it is so cold here. The other thing I am being told is to put straw around them about 12 inches high for the winter. I have been doing this but since my roses are hardy for zone 5 I was wondering if I really need to do this. CG, Spokane

A: Yes, I do grow roses and the majority of them are own-root (non-grafted) roses, which means they are quite winter-hardy and do not require mulching for the winter. If you have grafted roses, you will definitely want to mulch them since the graft is the one weak point on a rose. Re: pruning them, if you have any particularly long canes (such as 4′ or longer), I would recommend trimming them back so they won’t whip around in the winter winds. In general, regular pruning is discouraged here after about Labor Day because pruning tends to encourage tender new growth that is susceptible to winter kill.

Q: One of my hanging begonias is dropping the bloom before it even begins to open. I thought it may be too much water….but the leaves are not turning yellow. Any ideas? BN, Coolin, ID

A: There are 2 common causes of blossoms dropping off begonia plants: 1) overwatering them or 2) locating them where they get too much sun. Seems like #1 is the more common cause, though. Not sure if you’re growing tuberous begonias, but if you are, here’s a factsheet on them that might be helpful: http://www.spokane-county.wsu.edu/spokane/eastside/Fact%20Sheets/C007%20Tuberous%20Begonia%2007.pdf. I’d poke my finger into the potting soil down to the 1st or 2nd knuckle and see how damp it seems. Good luck!

Q: Your column in the June 26 Sunday Spokesman about heucheras has prompted me to send you a question about them. In the spring of 2015 I planted several ‘Carnival Peach Parfait’ heucheras and they’ve done very well. Last year they had a few short flower spikes but the blooms didn’t open. This year the plants are bigger and have lots of flower spikes but after several weeks the flowers haven’t opened. Are they not supposed to open? MJB, Moscow, Idaho

A: Heuchera blossoms tend to be quite tiny, so I think your ‘Carnival Peach Parfait’ heucheras are doing exactly what they should be doing. There are some cultivars that have a bit larger flowers but, for the most part, heuchera flowers are rather diminutive, taking a back seat to their amazing leaves!

Q: What does deadheading mean? I can snap off older marigold heads easily; I can pull flopped-over petunia flowers easily. I cannot remove daisies, for example, with my fingers so what does deadheading really mean? Do I cut certain things off with snippers? SS, Spokane

A: Deadheading is the removal of spent flowers to either make the plant continue blooming (i.e., flowering plants) or to prevent a plant from self-sowing (i.e., a plant that could be invasive). In the first case, if you don’t remove the spent flowers, the plant tends to stop blooming because it’s whole purpose in life is to have some flowers be pollinated, set seed and die. By removing the spent flowers, you can keep the blooming process going in most cases so the plant won’t focus all of its energy on maturing the seeds in the flower heads but rather, on blooming again. Yes, there are certain flowers you can’t snap off with your fingers so you’ll need to use scissors or pruners, or something along those lines. I would remove as many spent flowers as is feasible for you. However, I like to leave the late summer flower heads on plants like bee balm, black-eyed Susans, globe thistle, and coneflowers so birds will have seeds to eat during the winter months. It’s great fun watching birds landing on the seedheads and eating the seeds!