Lonefire + Soul Charge = Shooting Quasar Dragon
Before l After
Example:1.Normal summon Lonefire
2.Tribute Lonefire for second Lonefire
3.Tribute second Lonefire for Dandylion
4.SS both Lonefires from grave via Soul Charge
5.Tribute Dandylion for Spore
6.Synchro summon Formula Synchronwith token & Spore
7.Banish Dandylion, SS Spore from grave & synchro summon Hyper Librarian with Spore & second token
9.Tribute any  Lonefire for Mystic Macrocorpa Seed & decrees it's level by 1
10.Synchro summon Naturia Beast/Scarred Warrior with Mystic Macrocorpa Seed & Second Lonefire
11.Synchro summon Quasar with Formula Synchron, Hyper Librarian & Naturia Beast/Scarred Warrior

Lonefire + Instant Fusion/Reinforcement of the Army/Spell Striker = Shooting Star Dragon
Before l After
Example: 1.Normal summon Lonefire & special summon level 3 earth monster
2.Tribute Lonefire for second Lonefire
3.Tribute Second Lonefire for Dandylion
4.Xyz summon Meliae with Dandylion & level 3 EARTH monster
5.Detach Dandylion & SS Lonefire from grave
6.Tribute Meliae for Spore & synchro summon Formula Synchron with Spore & token
7.Banish Dandylion, SS Spore from grave and synchro summon Stardust Dragon with Spore, Lonefire and token
8.Synchro summon Shooting Star Dragon with Stardust Dragon& Formula Synchron

Mathematician + Super Solar Nutrient = Lonefire + Chirubimé, Princess of Autumn Leaves + Meliae of The Trees
Before l After
Example: 1.Normal summon Mathematician & dump Dandylion in grave
2.Tribute token & SS lonefire from deck via Super Solar Nutrient
3.Tribute Lonefire & SS second Lonefire
4.tribute second token & SS Mystic Macrocorpa Seed from deck
5.Xyz summon Meliae with Mathematician & Mystic Macrocorpa & detach to SS lonefire from grave
5.Tribute Lonefire to SS Chirubimé

Lonefire + Redox, Dragon Ruler of Boulders + Level 3 EARTH Monster = Felgrand/Leo, Guardian of the Sacred Tree or 2 Plant Princesses
Before l After
Example 1: 1.Normal summon Lonefire & tribute for plant princess
2.Discard Dandylion via Redox and SS Lonefire from grave
3.Tribute Lonefire for Mystic Macrocorpa Seed, lower level by 1 and synchro summon leo with Seed and Plant Princess
Example 2: 3.Tribute Lonefire for second Plant Princess and/or Xyz summon Felgrand with both Plant Princesses

Monsters

Chirubimé, Princess of Autumn Leaves
Your opponent cannot target face-up Plant-Type monsters for attacks, except this one. If this card in your possession is sent to your Graveyard by your opponent's card (either by battle or by card effect): You can Special Summon 1 Plant-Type monster from your Deck, except "Chirubimé, Princess of Autumn Leaves".

A 2800 wall that protects other plant type monsters from attacks. It's usually my go-to Princess first turn because it helps secure future Meliae plays.

Talaya, Princess of Cherry Blossoms
This card gains 100 ATK for each Plant-Type monster you control. Other Plant-Type monsters on the field cannot be destroyed by card effects.

Talaya protects other plants from Card Destruction. Getting both copies on board gives them at least 3100 atk and destruction immunity. Judgement Dragon ain't ****.

Mathematician
When this card is Normal Summoned: You can send 1 Level 4 or lower monster from your Deck to the Graveyard. When this card is destroyed by battle and sent to the Graveyard: You can draw 1 card.

Mathematician's built in Foolish Burialeffect speeds up your plays immensely and can combo with multiple cards in the deck. Before Mathematician, unless you had lonefire or Foolish Burial, you would usually have to summon 2 meliaes to use lonefire first turn. A great addition.

Spell Striker
You can Special Summon this card (from your hand) by banishing 1 Spell Card from your Graveyard. This card can attack your opponent directly. You take no battle damage from attacks involving this card.

A combo card that helps facilitate meliae plays. There are other cards that can do the same thing but I've found Spell Striker easier to summon but it's really up to personal preference.

Mystic Macrocarpa Seed
Cannot be used as a Synchro MaterialMonster, except for the Synchro Summon of an EARTH monster. You can target 1 EARTH monster on the field; reduce its Level by 1. You can use the effect of "Mystic Macrocarpa Seed" up to twice per turn.

This card is amazing. I used to run Naturia Rosewhip and Naturia Cosmobeet but after seeing Chric Leblanc's build, I decided to use this card instead. Seed can do both Rosewhip and Cosmobeet's job AND be a target for Super Solar Nutrient. It's utility is too good to pass up.

Crane Crane
When this card is Normal Summoned: You can target 1 Level 3 monster in your Graveyard; Special Summon that target. Its effects are negated. You can only use this effect of "Crane Crane" once per turn.

Crane Crane is a 1 card synchro/xyz. The reason I don't run him @3 is because I don't really want to open with him. You're not going to get his effect off first turn very often, so i'd rather draw him afterwards.

Spells

Instant Fusion
Pay 1000 Life Points; Special Summon 1 Level 5 or lower Fusion Monster from your Extra Deck. (This Special Summon is treated as a Fusion Summon.) It cannot attack, and is destroyed during the End Phase. You can only activate 1 "Instant Fusion" per turn.

Another combo piece. Very easy to get out but again, it's preference.

Super Solar Nutrient
Activate this card by Tributing 1 Level 2 or lower Plant-Type monster; Special Summon 1 Plant-Type monster from your hand or Deck whose Level is less than or equal to the Level the Tributed monster had on the field +3. When this card leaves the field, destroy that monster. When that monster leaves the field, destroy this card.

Another important card that speeds up your plays. I used to run Miracle Fertilizer but replaced it with this when I realized how easy it it was to get a target on board. You can dump dandy with Mathematician, detach Dandylion from melia or drop Macrocorpa Seed's lv to 1.

Traps

Raigeki Break
Discard 1 card to target 1 card on the field; destroy it.

Basically a discard outlet for plant princess since they're complete bricks in hand. PWWB or Divine Wrath are good alternatives, I just prefer Raigeki Break.

Mariña, Princess of Sunflowers
If exactly 1 other Plant-Type monster you control (and no other cards) is destroyed by battle or by card effect and sent to the Graveyard: You can target 1 card your opponent controls; destroy that target. This card must be face-up on the field to activate and to resolve this effect.

If only Mariña had a halfway decent effect i'd try to make room for her but alas.. she doesn't. The only thing notable about her is that she can loop with Lord Poison but not much else I can say. idk I just feel i'd get more bang for my buck with a second Talaya.

Sylvans

Sylvans would be pretty good in here since you have an easy way of keeping plant princess out of your hand. I'm not very experience with sylvans and honestly, if you're focusing purely on flower princess and meliae, then you're just playing a weaker sylvan deck :/.

Madolche

Madolches actually make a really good rank 3 engine for meliae. I actually used to run madolche but with the addition of soul charge and mathematician, there wasn't any room left to keep them.

Junk Forward
Marauding Captain
Mimimic
Elder of the Six samurai

Other level 3 earths that you can spam on field.

Miracle Fertilizer

Great Card, I just don't have room for it and Soul Charge is all around better anyway.

Trade-In

With plant princesses being lv 8; why am I not running Trade-In? Because they're not searchable targets, that's why. Throwing in inconsistency to deal with inconsistency is not very appealing to me. You're better off with discard traps.