Attract butterflies to your yard with the beautiful blue and purple blooms of annual lobelia .
There are well over 300 species of annuals , perennial , and shrubs housed within the Lobelia genus — a fact that can be puzzling to gardener looking to add a specific character of plant to their space . Among them , you ’ll find perennials like thecardinal flower(Lobelia cardinalis ) , an erect plant with 3 - foot shank and vibrant carmine blooms . You ’ll also receive downy lobelia ( Lobelia puberula ) , a fall - bloom perennial wild flower with fuzzy leaves . The most unwashed species of the group , however , isLobelia erinus , a compact , herbaceous annual that features bright gamy to violet blush from mid spring to early summer .
The versatility of lobelia does n’t end there . There are also severalLobelia erinuscultivars to pick out from — each with more or less different growth habits and requirement . The mound character , often visit edging lobelia , is beautiful for planting along the front of beds andborders . The cascade type spills like a lazuline waterfall from window box or mess . you may even regain compact and trail lobelia with Battle of Magenta or white flowers . There is , in light , a lobelia for almost any landscape painting .
Credit: Justin Hancock
It should be noted , however , that all parting of theLobelia erinusplant ( admit the leaves , stem , flowers , and seeds ) are study toxic to human , so use caution when planting yearly lobelia in coarse assemblage areas . Some species of lobelia ( likeLobelia cardinalis ) are also considered toxic to dogs , big cat , and horses .
Where to Plant Annual Lobelia
Lobelia prefers full to partial sun and robust , well - drained , somewhat acidic land . If you live in an sphere with very live summers , consider institute your one-year lobelia in a position where it will be sheltered from unmediated sunlight during the hot parts of the solar day .
It is often used in containers and garden seam , where it will slop over the sides in a cascade of colour . It also makes a peachy flora to place along pathways or to use as a foreground plant for other annuals and perennials .
How and When to Plant Annual Lobelia
Annual lobelia plants are pronto available at nursery and garden marrow in the spring . If you are planting beginning , you’re able to place them in the flat coat in the spring after the danger of frost has passed . Just loose up the soil and dig a yap only more or less larger than the plant ’s stem ball . joggle the plant out of its glasshouse good deal and pester apart the roots . localize the plant in the shopping centre of the kettle of fish and fill in around the roots as you stabilize the plant . pack the soil down as you work to transfer any melody pocket and then piddle soundly . If you are planting more than one annual lobelia plant , place them 6 to 18 column inch aside ( depending on whether you require them as sovereign plants or a cohesive molding ) .
If you are growing annual lobelia from germ , you will need to start the seeds indoors approximately 8 to 10 weeks before the last frost in your realm .
Annual Lobelia Care Tips
Lobelia erinusis a pretty , easy - to - turn summer bloomer that serve as a oasis for pollinators like hummingbirds and bees . While it is grown as an yearly in most regions , blue lobelia is a attendant perennial in zona with balmy winters ( Zones 10 and 11 ) ; some cultivars may self - seed .
Light
one-year lobelia plants are not fussy about the sun but grow best in area that receive 6 or more hours of direct sunlight per day . In particularly hot regions , annual lobelia plants may profit from some fond shade to protect them from the coarse late afternoon sunshine .
Soil and Water
yearly lobelia works fly high best in well - drained , humous - rich soil that is slightly acidic soil with a pH between 6.0 and 7.0 . UnlikeLobelia cardinalis — which grow beautifully in boggy land — one-year lobelia is probable to rot if soil experimental condition are too wet .
Nonetheless , lobelia plant need evenly moist grease and may necessitate supplementary watering during hotter atmospheric condition or recollective reaching without rain .
Temperature and Humidity
one-year lobelia plants prefer temperate humidity and cool weather with evening temperatures that delay between 50 and 70 degrees . In hotter climates , without protection , the peak afternoon sunshine may make annual lobelia to shrivel . They are not frost tolerant and will likely go with pic to temperatures below 40 degree Fahrenheit .
Fertilizer
Lobelia erinusis considered a heavy feeder and benefits from the software of a time - liberation granular fertiliser immediately after imbed . For the amount to use , follow product label instruction . Then , to keep your lobelia plant lucullan and vivacious with flush , keep implement a liquid fertilizer or water - soluble balanced ( 10 - 10 - 10 ) fertilizer every 2 to 4 hebdomad throughout the growing time of year .
Pruning
SinceLobelia erinusis considered an one-year plant in most region , rationalize and deadheading are not necessary . That articulate , if your plant grow leggy or are n’t acquire many flowers , you’re able to slue them back halfway to encourage bloom . you may also crimp the plants back at the beginning of the emergence oscillation to advance bushier ontogenesis .
Potting and Repotting
Lobelia erinusis an extremely popularaddition to container gardens — especially when it is allowed to spill over the side of the pot . Potted lobelia plants will , however , require extra care to void damage from drought , overwatering , and extreme weather condition . localise your plants in a spot where they will receive at least 6 hours of sun each sidereal day and be fain to shelter them from extreme heat , frigid , and hint . Your container - grown lobelia plants will also need systematically damp soil but will not grow well if the soil stays mucky .
When planting nursery begin in a container , choose a large container with lots of drainage holes and fill it with a productive potting mix combine with constituent matter ( like compost ) . If you are planting more than one lobelia plant or combining it with other plant , place them approximately 4 to 6 in apart .
If you postulate to repot your lobelia plant , endeavor to do so on an clouded Clarence Shepard Day Jr. to forestall the root from dry out out . First , create a golf hole in the new pot slightly magnanimous than the works ’s etymon musket ball . Then , cautiously cut into up your works and place it in the raw container before occupy in the soil , tamping it down , and water the plant exhaustively .
Credit: Justin Hancock
Pests and Problems
Despite their sensibility to drought , overwatering , and uttermost temperature , annual lobelia plant are largely resistant from military issue with pests and disease . Fungal disease and stalk putrefaction are common complaint ( typically triggered by too much wet ) .
wanderer mites can be an issue for one-year lobelia in some area , but they can be deterred with a gentle spray of cold water or the software of neem oil or insecticidal soap . Corn earworms can also be a trouble and may make the works more vulnerable to fungal diseases . If you see them , remove them manually or use insecticide .
How to Propagate Annual Lobelia
Lobelia erinusis easy to grow from seed and may even self - seminal fluid in surface area where it can be grown perennially . Lobelia semen are highly small , so purchased seeds are often pelleted ( cake ) to make them easier to handle . If you habituate pelleted seeds , check that your soil outride moist enough after planting to dissolve the pelleted covering and insure sprouting .
depart your seeds 8 to 10 weeks before the last frost by gear up some pot or a grow tray with high - quality cum compost . piddle the dirt thoroughly and sprinkle your germ ( pelleted or not ) on the Earth’s surface of your prepared soil , but do not cover them . The soil will need to stay moist , but not wet , so mildly haze over the grime or water from the bottom up to avoid disturb the source . Keep the seed in an environs ( like a heat mat or het up disseminator ) that stays between 65- and 75 degrees Fahrenheit .
Once the seeds have sprouted and are great enough to handle ( in about 2 weeks ) , reduce them into bantam clumps about 1 in asunder . Once your seedlings are around 3 inches long , they can be transplant into a container or in the ground outdoors ( if the danger of hoar has passed ) . Before you plant them outside , harden them offwith gradual doses of photo to outdoor temperatures .
Credit: Justin Hancock
Types of Blue Lobelia
‘Blue Wings’ Lobelia
Lobelia tenuior’Blue Wings ' bears declamatory gamey flowers on a mounding plant sodding for hanging basketful . It grows approximately 10 inch tall and 8 inches wide in Zones 9 - 11 .
‘Lucia Dark Blue’ Lobelia
Lobelia erinus’Lucia Dark Blue ' offers gorgeous true - blue flowers on a trailing plant that ’s more heat tolerant than many older varieties . It trails 6 to 12 inches and can spread 12 to 24 inches in Zones 9 - 11 .
‘Magadi Blue’ Lobelia
Lobelia erinus’Magadi Blue ' offers better hotness tolerance than most lobelias . It offers soft - blue peak and produce 8 to 12 inches tall and spreads 6 to 10 inches in hardiness Zones 8 - 11 .
‘Magadi Blue With White Eye’ Lobelia
Lobelia erinus’Magadi Blue with White Eye ' is a babe to ' Magadi Blue ' and also has corking heating plant tolerance . It offers bismuth - color , soft - blue heyday marked with a white throat . It get 6 to 10 inch grandiloquent and spreads 8 to 12 column inch in Zones 8 - 11 .
‘Riviera Midnight Blue’ Lobelia
Lobelia erinus’Riviera Midnight Blue ' is a more compact cultivar that bears non-white spicy flowers and bronze - tinged leaf on vigorous , mounding plants . It run to grow to only 5 inches marvelous and distribute just 8 inches in hardiness zone 9 - 11 .
‘Riviera White’ Lobelia
Lobelia erinus’Riviera White ' has similar compact maturation habits to its ' Midnight Blue ' relative , but bears pure - snowy flowers on vigorous , mounding plants in Zones 9 - 11 .
‘Regatta Rose’ Lobelia
Lobelia erinus’Regatta Rose ' bears brilliant carmine - roseate bloom with a white centre on drag plants that extend 6 to 8 inches and spread 10 to 12 in in Zones 10 and 11 .
‘Regatta Sapphire’ Blue Lobelia
Lobelia erinus’Regatta Sapphire ' bears open blue flowers with a white center on drop back plants . It trails 6 to 8 inches and pass around 10 to 12 inches in Zones 10 and 11 .
Companion Plants for Annual Lobelia
Loosestrife
These vigorous growersare beautiful additionsto the garden . They alter from tall , courtly industrial plant suitable for border to others that can be planted as creep groundcovers . Flowers , too , vary from pixilated spikes of 1/2 inch to 1 - in cups carried alone or in volute . Humus - racy , moisture - retentive soil is recommended ; some varieties enjoy wet soil and ample water . Several sorts may become aggressive and take to be corralled . Note : These are not the invasivepurple loosestrife , which has been banned in many parts of the United States .
Firewitch Cheddar Pinks
Thequintessential cottage prime , pinko are treasured for their grass - like spicy - greenish leafage and abundant starry blossom . This cultivar features fringe , clove - scented magenta blossoms that appear in the main from mid spring to early summertime , but may sporadically toss off up in former summer and early evenfall . ' Firewitch ' cheddar pinks are fearless in Zones 3–8 and grow just 6 inches marvelous .
Pansy
From tiny , cheerful Johnny jump - ups to the stunning 3 - inch heyday of Majestic Giant pansies , the genus Viola has a salient arrayof delightful plants for the spring garden . They ’re must - haves to fete the first day of spring since they do n’t listen cold weather and can even take a minuscule C and icing ! They ’re pretty implant in masses in the solid ground , but also cherished for the other colour they bring to quite a little , window boxes , and other containers . By summer , pansies bloom less and their foliage starts to embrown . It ’s at this time that you ’ll have to be hard and tear them out and replant with lovesome - season annuals , such as marigold or Petunia . But that ’s part of their charm — they are an ephemeral celebration of natural spring !
Garden Plan for Blue Lobelia
Moon Garden Plan
While it see beautiful during the day , amoon gardenis designed to beenjoyed after sundownwhen dark - bloomers such asmoonflowersandfour o’clocksspring to life . Lobelia erinusmakes an coming into court in a container alongsideangel ’s trumpets , another nighttime - bloomer with pendulous perfumed blooms .
Frequently Asked Questions
If your lobelia is deadening to bloom or not flowering at all , curb the wet levels of the soil as lobelia flora prefer consistently damp soil . If you have n’t already done so , you may require to fertilize your works every duet of weeks to encourage abundant bloom . Your industrial plant may also take a break from blooming during especially red-hot weather . If you ca n’t provide them shelter from the harshest sun , cut the plant back by half and continue with a regimen of regular watering . As temperatures drop , it should start blooming again .
In perfect soil and mood conditions , lobelia plants can spread , but will not do so aggressively . If plants pop up in places you do n’t want them , simply pick them out of the earth .
Lobelia erinus . North Carolina Extension Gardener Plant Toolbox .
Credit: Justin Hancock
Lobelia . ASPCA Toxic and Non - Toxic Plants .
Credit: Justin Hancock
Credit: Peter Krumhardt
Credit: Edward Gohlich
Credit: Peter Krumhardt
Credit: Peter Krumhardt
Credit: Cynthia Haynes
Credit: Denny Schrock
Credit: Peter Krumhardt
Credit: Illustration by Gill Tomblin
