Just a couple of thoughts from a quick look:
Freezing Rain: The #1 thing you want to enhance is Recharge, as you want this up as often as possible. Tempered Readiness has almost no recharge. Also, if you use Snow Storm or Roots, the slow enhancement is doing you no good. If you want to put a set in it, look at the Lady Grey Defense Debuff set for some decent bonuses, but you will need to replace one of them with a Recharge to get enough Recharge.
Also with Creepers and Tornado, you want to maximize Recharge to get them out as often as possible. This is more important than any other enhancement.
Lightning Storm: Try Dam/Rech and Dam/EndRdx/Rech from Thunderstrike and Entropic Chaos, and Dam/Rech and Chance for Hold from Devastation. It allows you get get two Lightning Storms out at once, and the Chance for Hold is great in the Storm.
LOCAL MAN! The most famous hero of all. There are more newspaper stories about me than anyone else. "Local Man wins Medal of Honor." "Local Man opens Animal Shelter." "Local Man Charged with..." (Um, forget about that one.)
Guide Links: Earth/Rad Guide, Illusion/Rad Guide, Electric Control
I finally acquired a couple of LotG +Recharge, and respeced my exceedingly purple plant/storm controller. The main change was to slot four LotG, and to 6-slot both Freezing Rain and Creepers. (Previously, both FR and CC only had the default slot.)
Hero Plan by Mids' Hero Designer 1.401
http://www.cohplanner.com/
[u]Click this DataLink to open the build![u]
Fumina Hara: Level 50 Magic Controller
Primary Power Set: Plant Control
Secondary Power Set: Storm Summoning
Power Pool: Fitness
Power Pool: Speed
Power Pool: Leaping
Power Pool: Leadership
Ancillary Pool: Stone Mastery
Hero Profile:
Level 1: Entangle -- GravAnch-Immob(A), GravAnch-Immob/Rchg(3), GravAnch-Acc/Immob/Rchg(3), GravAnch-Acc/Rchg(5), GravAnch-Immob/EndRdx(5)
Level 1: Gale -- Acc-I(A)
Level 2: Strangler -- BasGaze-Acc/Hold(A), BasGaze-Acc/Rchg(7), BasGaze-Rchg/Hold(7), BasGaze-EndRdx/Rchg/Hold(9)
Level 4: Roots -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(11), Posi-Dmg/Rchg(11), Posi-Dmg/Rng(13), Posi-Dam%(13), TotHntr-Dam%(36)
Level 6: Spore Burst -- FtnHyp-Sleep(A), FtnHyp-Sleep/Rchg(9), FtnHyp-Acc/Sleep/Rchg(15), FtnHyp-Acc/Rchg(15), FtnHyp-Sleep/EndRdx(17)
Level 8: Seeds of Confusion -- CoPers-Conf%(A), CoPers-Conf/Rchg(19), CoPers-Acc/Conf/Rchg(19), CoPers-Acc/Rchg(21), CoPers-Conf/EndRdx(21)
Level 10: Steamy Mist -- ResDam-I(A), LkGmblr-Rchg+(25), S'fstPrt-ResDam/Def+(29)
Level 12: Swift -- Run-I(A)
Level 14: Health -- Mrcl-Rcvry+(A), Mrcl-Heal(23), Numna-Regen/Rcvry+(48), Numna-Heal(50)
Level 16: Freezing Rain -- Achilles-ResDeb%(A), RechRdx-I(17), RechRdx-I(31), ImpSwft-Dam%(31), Posi-Dam%(33), LdyGrey-%Dam(36)
Level 18: Hasten -- RechRdx-I(A), RechRdx-I(23), RechRdx-I(40)
Level 20: Stamina -- EndMod-I(A), P'Shift-EndMod(25)
Level 22: Combat Jumping -- LkGmblr-Rchg+(A), LkGmblr-Def(48)
Level 24: Vines -- BasGaze-Acc/Hold(A), BasGaze-EndRdx/Rchg/Hold(27), BasGaze-Acc/Rchg(29), BasGaze-Rchg/Hold(34)
Level 26: Carrion Creepers -- Posi-Dmg/Rchg(A), Det'tn-Dmg/Rchg(27), AirB'st-Dmg/Rchg(33), ExStrk-Dam%(33), TotHntr-Dam%(40), ImpSwft-Dam%(42)
Level 28: Super Jump -- Zephyr-ResKB(A)
Level 30: Thunder Clap -- Amaze-Stun(A), Amaze-Stun/Rchg(31), Amaze-Acc/Stun/Rchg(34), Amaze-Acc/Rchg(37), Amaze-EndRdx/Stun(37)
Level 32: Fly Trap -- C'Arms-Acc/Rchg(A), C'Arms-Acc/Dmg/Rchg(34), C'Arms-Acc/Dmg(39), C'Arms-Dmg/EndRdx(39)
Level 35: Tornado -- C'Arms-Acc/Rchg(A), C'Arms-Acc/Dmg(36), C'Arms-Acc/Dmg/Rchg(37), C'Arms-Dmg/EndRdx(42)
Level 38: Lightning Storm -- Decim-Acc/Dmg(A), Decim-Dmg/EndRdx(39), Decim-Acc/Dmg/Rchg(40), Decim-Dmg/Rchg(43), Decim-Acc/EndRdx/Rchg(45)
Level 41: Fissure -- FrcFbk-Rechg%(A), Posi-Acc/Dmg(42), Posi-Dmg/EndRdx(43), Posi-Dmg/Rchg(43), Posi-Dmg/Rng(46), Posi-Acc/Dmg/EndRdx(46)
Level 44: Seismic Smash -- Hectmb-Dmg(A), Hectmb-Dmg/Rchg(45), Hectmb-Acc/Dmg/Rchg(45), Hectmb-Acc/Rchg(46), Hectmb-Dmg/EndRdx(48)
Level 47: Rock Armor -- LkGmblr-Rchg+(A), LkGmblr-Def(50)
Level 49: Maneuvers -- LkGmblr-Rchg+(A), LkGmblr-Def(50)
------------
Level 1: Brawl -- Empty(A)
Level 1: Sprint -- ULeap-Stlth(A)
Level 2: Rest -- Empty(A)
Level 1: Containment
Anyone have any suggestions to further tweak my build? 
Hazel Black - Mind/Psi D
Stephanie Winters - Nightwidow
Jacqui Frost - Cold/Ice D
Jacqui Embers - Fire/Kin C
Simone Templar - Fire/MM B
Mallory Woods - Kin/Rad D
Sanguine Melody - Grav/Sonic C
Fumina Hara - Plant/Storm C
Nutmeg - Warshade
Lauren Wu - SS/WP B
Okay so after re-working my build a bit this is what I came up with. I feel it is actually a lot cheaper and also a lot safer too. I want her to be able to solo 4-6 man team maps come I16 so I went for more S/L Defense. I am most worried about my recovery rate at this point as Storm Summoning is an Endurance hog. My bonus priority was:
1-Recovery
2-Recharge
3-Defense
4-Resistance
Hero Plan by Mids' Hero Designer 1.401
http://www.cohplanner.com/
[u]Click this DataLink to open the build![u]
Azshalla: Level 50 Natural Controller
Primary Power Set: Plant Control
Secondary Power Set: Storm Summoning
Power Pool: Fitness
Power Pool: Speed
Power Pool: Fighting
Power Pool: Leaping
Ancillary Pool: Stone Mastery
Hero Profile:
Level 1: Entangle -- Entrpc-Acc/Dmg(A), Entrpc-Dmg/EndRdx(3), Entrpc-Dmg/Rchg(7), Entrpc-Dmg/EndRdx/Rchg(25), Entrpc-Heal%(43)
Level 1: Gale -- Acc-I(A)
Level 2: Strangler -- BasGaze-Acc/Hold(A), BasGaze-Acc/Rchg(3), BasGaze-Rchg/Hold(7), BasGaze-EndRdx/Rchg/Hold(37), BasGaze-Acc/EndRdx/Rchg/Hold(43)
Level 4: Roots -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(5), Posi-Acc/Dmg/EndRdx(5), Enf'dOp-Acc/EndRdx(15), Dmg-I(19)
Level 6: Hurdle -- Jump-I(A)
Level 8: Seeds of Confusion -- Mlais-Acc/Rchg(A), Mlais-EndRdx/Conf(9), Mlais-Acc/EndRdx(9), Mlais-Conf/Rng(11), Mlais-Acc/Conf/Rchg(15), Mlais-Dam%(17)
Level 10: Steamy Mist -- EndRdx-I(A), ResDam-I(11), S'fstPrt-ResDam/EndRdx(46), S'fstPrt-ResDam/Def+(50)
Level 12: Hasten -- RechRdx-I(A), RechRdx-I(13), RechRdx-I(13)
Level 14: Super Speed -- Run-I(A)
Level 16: Freezing Rain -- CtlSpd-EndRdx/Rchg/Slow(A), ImpSwft-EndRdx/Rchg/Slow(17), TmpRdns-EndRdx/Rchg/Slow(19), P'ngTtl-EndRdx/Rchg/Slow(40)
Level 18: Health -- Heal-I(A)
Level 20: Stamina -- EndMod-I(A), EndMod-I(21), EndMod-I(21)
Level 22: Vines -- BasGaze-Acc/Hold(A), BasGaze-Acc/Rchg(23), BasGaze-Rchg/Hold(23), BasGaze-EndRdx/Rchg/Hold(25), BasGaze-Acc/EndRdx/Rchg/Hold(34)
Level 24: Hurricane -- EndRdx-I(A)
Level 26: Carrion Creepers -- RechRdx-I(A), RechRdx-I(27), RechRdx-I(27), Acc-I(29), Posi-Dam%(29), ImpSwft-Dam%(31)
Level 28: Boxing -- Acc-I(A)
Level 30: Tough -- Aegis-ResDam/EndRdx(A), TtmC'tng-ResDam/EndRdx(31), ImpArm-ResDam/EndRdx(31), RctvArm-ResDam/EndRdx(34)
Level 32: Fly Trap -- C'Arms-Acc/Rchg(A), C'Arms-Acc/Dmg(33), C'Arms-Dmg/EndRdx(33), C'Arms-Acc/Dmg/Rchg(33), C'Arms-EndRdx/Dmg/Rchg(34)
Level 35: Tornado -- C'Arms-Dmg/EndRdx(A), C'Arms-EndRdx/Dmg/Rchg(36), ExRmnt-Dmg/EndRdx(36), ExRmnt-EndRdx/Dmg/Rchg(36), RechRdx-I(37), RechRdx-I(37)
Level 38: Lightning Storm -- Thundr-Dmg/Rchg(A), Thundr-Dmg/EndRdx/Rchg(39), Entrpc-Dmg/Rchg(39), Entrpc-Dmg/EndRdx/Rchg(39), Dev'n-Dmg/Rchg(40), Dev'n-Hold%(40)
Level 41: Fissure -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(42), Posi-Dmg/Rchg(42), Posi-Dmg/Rng(42), Posi-Acc/Dmg/EndRdx(43), FrcFbk-Rechg%(46)
Level 44: Rock Armor -- GftotA-Def/EndRdx(A), GftotA-Def(45), LkGmblr-Def/EndRdx(45), LkGmblr-Def/EndRdx/Rchg(45), LkGmblr-Rchg+(46)
Level 47: Weave -- GftotA-Def/EndRdx(A), GftotA-Def(48), LkGmblr-Def/EndRdx(48), LkGmblr-Def/EndRdx/Rchg(48), LkGmblr-Rchg+(50)
Level 49: Combat Jumping -- Zephyr-ResKB(A), Zephyr-Travel(50)
------------
Level 1: Brawl -- Acc-I(A)
Level 1: Sprint -- EndRdx-I(A)
Level 2: Rest -- RechRdx-I(A)
Level 1: Containment
------------
[u]Set Bonus Totals:[u]<ul type="square">[*]2.5% DamageBuff(Smashing)[*]2.5% DamageBuff(Lethal)[*]2.5% DamageBuff(Fire)[*]2.5% DamageBuff(Cold)[*]2.5% DamageBuff(Energy)[*]2.5% DamageBuff(Negative)[*]2.5% DamageBuff(Toxic)[*]2.5% DamageBuff(Psionic)[*]3% Defense(Smashing)[*]3% Defense(Lethal)[*]3% Defense(Fire)[*]3% Defense(Cold)[*]11.1% Defense(Energy)[*]11.1% Defense(Negative)[*]3% Defense(Psionic)[*]3% Defense(Melee)[*]11.8% Defense(Ranged)[*]3% Defense(AoE)[*]2.25% Max End[*]55% Enhancement(RechargeTime)[*]2.5% Enhancement(Confused)[*]9% Enhancement(Accuracy)[*]38.2 HP (3.75%) HitPoints[*]Knockback (Mag -4)[*]Knockup (Mag -4)[*]MezResist(Confused) 15.3%[*]MezResist(Held) 12.5%[*]MezResist(Immobilize) 12.5%[*]MezResist(Sleep) 12.5%[*]MezResist(Stun) 12.5%[*]MezResist(Terrorized) 12.5%[*]24% (0.4 End/sec) Recovery[*]52% (2.21 HP/sec) Regeneration[*]1.89% Resistance(Smashing)[*]1.89% Resistance(Lethal)[*]3.15% Resistance(Fire)[*]3.15% Resistance(Cold)[/list]
Man oh man do I love this controller. First one I got past level 20 and it has been a blast, Plant/Storm is an AoE beast! Right now I am at level 40 and I want to start planning an IO build for this toon and I think the one I have come up with is pretty good. I want to get perma-Hasten so I can have perma-Creepers and multiple Tornadoes up. This is just an initial start up build, with purples added later. With this build I have about nine seconds of Hasten downtime, which is not too bad, IMO.
Hero Plan by Mids' Hero Designer 1.401
http://www.cohplanner.com/
[u]Click this DataLink to open the build![u]
Azshalla: Level 50 Natural Controller
Primary Power Set: Plant Control
Secondary Power Set: Storm Summoning
Power Pool: Fitness
Power Pool: Speed
Power Pool: Leaping
Ancillary Pool: Stone Mastery
Hero Profile:
Level 1: Entangle -- Entrpc-Acc/Dmg(A), Entrpc-Dmg/EndRdx(3), Entrpc-Dmg/Rchg(7), Entrpc-Dmg/EndRdx/Rchg(19), Entrpc-Heal%(43)
Level 1: Gale -- Acc-I(A)
Level 2: Strangler -- BasGaze-Acc/Hold(A), BasGaze-Acc/Rchg(3), BasGaze-Rchg/Hold(7), BasGaze-EndRdx/Rchg/Hold(23), BasGaze-Acc/EndRdx/Rchg/Hold(46)
Level 4: Roots -- Posi-Acc/Dmg(A), Posi-Dmg/EndRdx(5), Posi-Dmg/Rchg(5), Posi-Dmg/Rng(15), Posi-Acc/Dmg/EndRdx(23), Posi-Dam%(37)
Level 6: Hurdle -- Jump-I(A)
Level 8: Seeds of Confusion -- Mlais-EndRdx/Conf(A), Mlais-Acc/EndRdx(9), Mlais-Dam%(9), Mlais-Acc/Rchg(15), Mlais-Conf/Rng(34), Mlais-Acc/Conf/Rchg(34)
Level 10: Steamy Mist -- EndRdx-I(A), ResDam-I(11), S'fstPrt-ResDam/Def+(11), LkGmblr-Rchg+(43)
Level 12: Hasten -- RechRdx-I(A), RechRdx-I(13), RechRdx-I(13)
Level 14: Super Speed -- Run-I(A)
Level 16: Freezing Rain -- TmpRdns-Rng/Slow(A), TmpRdns-Dmg/Slow(17), TmpRdns-Acc/EndRdx(17), TmpRdns-EndRdx/Rchg/Slow(19), TmpRdns-Acc/Dmg/Slow(40)
Level 18: Health -- Heal-I(A)
Level 20: Stamina -- EndMod-I(A), EndMod-I(21), EndMod-I(21)
Level 22: Snow Storm -- EndRdx-I(A)
Level 24: Vines -- BasGaze-Acc/Hold(A), BasGaze-Acc/Rchg(25), BasGaze-Rchg/Hold(25), BasGaze-EndRdx/Rchg/Hold(29), BasGaze-Acc/EndRdx/Rchg/Hold(31)
Level 26: Carrion Creepers -- RechRdx-I(A), Posi-Dmg/EndRdx(27), Posi-Dmg/Rchg(27), Posi-Dam%(29), TotHntr-Dam%(31), ImpSwft-Dam%(31)
Level 28: Hurricane -- EndRdx-I(A)
Level 30: O2 Boost -- EndRdx-I(A)
Level 32: Fly Trap -- C'Arms-Acc/Rchg(A), C'Arms-Acc/Dmg(33), C'Arms-Dmg/EndRdx(33), C'Arms-Acc/Dmg/Rchg(33), C'Arms-EndRdx/Dmg/Rchg(34), C'Arms-+Def(Pets)(46)
Level 35: Tornado -- ExRmnt-Acc/Rchg(A), ExRmnt-Acc/Dmg(36), ExRmnt-Dmg/EndRdx(36), ExRmnt-Acc/Dmg/Rchg(36), ExRmnt-EndRdx/Dmg/Rchg(37), Achilles-ResDeb%(37)
Level 38: Lightning Storm -- Thundr-Acc/Dmg(A), Thundr-Dmg/EndRdx(39), Thundr-Dmg/Rchg(39), Thundr-Acc/Dmg/Rchg(39), Thundr-Acc/Dmg/EndRdx(40), Thundr-Dmg/EndRdx/Rchg(40)
Level 41: Fissure -- Det'tn-Acc/Dmg(A), Det'tn-Dmg/EndRdx(42), Det'tn-Dmg/Rchg(42), Det'tn-Dmg/Rng(42), Det'tn-Acc/Dmg/EndRdx(43)
Level 44: Rock Armor -- LkGmblr-Def/EndRdx(A), LkGmblr-Def/Rchg(45), LkGmblr-Def/EndRdx/Rchg(45), LkGmblr-Def(45), LkGmblr-Rchg+(46)
Level 47: Earth's Embrace -- Dct'dW-Heal(A), Dct'dW-Rchg(48), Dct'dW-Heal/Rchg(48), Dct'dW-Heal/EndRdx(48), Dct'dW-EndRdx/Rchg(50), Dct'dW-Heal/EndRdx/Rchg(50)
Level 49: Combat Jumping -- Zephyr-ResKB(A), LkGmblr-Rchg+(50)
------------
Level 1: Brawl -- Acc-I(A)
Level 1: Sprint -- EndRdx-I(A)
Level 2: Rest -- RechRdx-I(A)
Level 1: Containment
------------
[u]Set Bonus Totals:[u]<ul type="square">[*]5.5% DamageBuff(Smashing)[*]5.5% DamageBuff(Lethal)[*]5.5% DamageBuff(Fire)[*]5.5% DamageBuff(Cold)[*]5.5% DamageBuff(Energy)[*]5.5% DamageBuff(Negative)[*]5.5% DamageBuff(Toxic)[*]5.5% DamageBuff(Psionic)[*]5% Defense[*]3% Defense(Smashing)[*]3% Defense(Lethal)[*]5.19% Defense(Fire)[*]5.19% Defense(Cold)[*]13.3% Defense(Energy)[*]13.3% Defense(Negative)[*]3% Defense(Psionic)[*]3% Defense(Melee)[*]12.4% Defense(Ranged)[*]7.38% Defense(AoE)[*]3.15% Max End[*]1.5% Enhancement(JumpSpeed)[*]25% Enhancement(Accuracy)[*]77.5% Enhancement(RechargeTime)[*]4% Enhancement(Heal)[*]2.5% Enhancement(Confused)[*]1.5% Enhancement(FlySpeed)[*]1.5% Enhancement(RunSpeed)[*]1.5% Enhancement(JumpHeight)[*]4% FlySpeed[*]26.7 HP (2.63%) HitPoints[*]4% JumpHeight[*]4% JumpSpeed[*]Knockback (Mag -4)[*]Knockup (Mag -4)[*]MezResist(Confused) 15.3%[*]MezResist(Held) 15.3%[*]MezResist(Immobilize) 12.5%[*]MezResist(Sleep) 14.2%[*]MezResist(Stun) 12.5%[*]MezResist(Terrorized) 14.7%[*]17.5% (0.29 End/sec) Recovery[*]30% (1.27 HP/sec) Regeneration[*]1.89% Resistance(Smashing)[*]1.89% Resistance(Lethal)[*]4.41% Resistance(Fire)[*]4.41% Resistance(Cold)[*]1.88% Resistance(Energy)[*]4.39% Resistance(Toxic)[*]1.26% Resistance(Psionic)[*]4% RunSpeed[*]1% XPDebtProtection[/list]